One-Word Substitution: Phrases and Their One-Word Answers

Instead of writing "a person who loves books", you can write one word: bibliophile. Instead of "a place where birds are kept", you can write aviary. This skill is called one-word substitution, and it makes writing shorter, sharper and more impressive. It is also a regular question in O Level, A Level and competitive examinations.

This guide explains how one-word substitution works, the Greek and Latin word parts that help you remember the answers, and how to use these words in sentences. Its main part gives 230 phrases with their one-word answers, grouped by theme, followed by sentences, commonly confused pairs, mistakes, key points, ten practice questions and a teacher activity.

It pairs with Synonyms in English and Idioms in English, and connects with Parts of Speech and Common Errors in English. Spelling in this guide follows British English.

1.What Is One-Word Substitution?

One-word substitution means replacing a phrase or a clause with a single word that has the same meaning. The one word is usually a noun or an adjective, and it often comes from Greek or Latin.

Why it matters. It makes writing concise and formal, and it shows range of vocabulary.
Where it is tested. Examinations ask you to choose the correct single word for a long phrase.
How it works. Learn the word together with the meaning, and use the word parts as clues.

2.Word Parts That Help You Remember

Many one-word substitutes are built from the same Greek and Latin parts. If you learn these, you can often work out the answer.

Word part	Meaning	Examples
phil-, -phile	love of	bibliophile (loves books), philanthropist (loves mankind), philatelist (loves stamps)
-phobia	fear of	claustrophobia (closed spaces), acrophobia (heights), xenophobia (foreigners)
-cide	killing	suicide, regicide, patricide, genocide, insecticide
-ology	the study of	biology, geology, etymology, ornithology
-cracy	rule or government by	democracy, autocracy, plutocracy, theocracy
-archy	rule by	monarchy, oligarchy, anarchy
-mania	an extreme urge	kleptomania, pyromania, bibliomania
mis-, miso-	hatred of	misanthrope, misogynist
omni-	all	omniscient, omnipotent, omnipresent
mono-, bi-, poly-	one, two, many	monogamy, bigamy, polygamy, polyglot
-arian	a person of an age or belief	centenarian, octogenarian, vegetarian
in-, il-, im-, ir-	not (with -able, -ible)	inaudible, illegible, incredible, invincible

3.One Word for a Person: Character and Belief

Phrase or definition	One word
a person who loves books	bibliophile
a person who loves mankind and helps others	philanthropist
a person who hates mankind	misanthrope
a person who hates women	misogynist
a person who knows many languages	polyglot
a person who is skilled in many fields of knowledge	polymath
a person who walks in his sleep	somnambulist
a person who talks in his sleep	somniloquist
a person who lives alone and avoids people	recluse
a person who gives up worldly comforts for spiritual reasons	ascetic
a person who enjoys fine food and drink	epicure
a person who loves his country	patriot
a person who betrays his country	traitor
a person who leaves his country to settle in another	emigrant
a person who comes to settle in a new country	immigrant
a person who lives outside his own country	expatriate
a person who cannot pay his debts	insolvent
a person who cannot read or write	illiterate
a person who is a hundred years old	centenarian
a person who is between seventy and seventy-nine	septuagenarian
a person who is between eighty and eighty-nine	octogenarian
a person who is between ninety and ninety-nine	nonagenarian
a person who does something for pleasure, not as a profession	amateur
a person who works without payment	volunteer
a person who does not believe in God	atheist
a person who says that God's existence cannot be known	agnostic
a person who doubts everything	sceptic
a person who is ignorant and stupid	ignoramus
a person who looks on the bright side of things	optimist
a person who expects the worst	pessimist
a person who thinks only of himself	egoist
a person who puts the interests of others first	altruist
a person who believes that everything is decided by fate	fatalist
a person who does not eat meat	vegetarian
a person who eats human flesh	cannibal
a person who is new to a task	novice
a person who is learning a trade	apprentice
a person who hoards wealth and spends as little as possible	miser
a person who is addicted to work	workaholic
a person who sneers at the sincerity of others	cynic
a person who walks on a tight rope	funambulist

4.One Word for a Profession or Specialist

Phrase or definition	One word
a person who writes poems	poet
a person who compiles a dictionary	lexicographer
a person who makes maps	cartographer
a person who collects stamps	philatelist
a person who collects coins	numismatist
a person who studies handwriting	graphologist
a person who keeps bees	apiarist
a person who studies insects	entomologist
a person who studies birds	ornithologist
a person who studies the stars	astronomer
a person who studies the earth's structure	geologist
a person who studies ancient remains	archaeologist
a doctor who treats teeth	dentist
a doctor who treats children	paediatrician
a doctor who treats skin diseases	dermatologist
a doctor who treats heart diseases	cardiologist
a doctor who treats diseases of the nerves	neurologist
a doctor who treats women's health	gynaecologist
a doctor who treats mental illness	psychiatrist
a doctor who treats cancer	oncologist
a doctor who treats kidney diseases	nephrologist
a doctor who treats bone and joint problems	orthopaedist
a person who tests eyesight and prescribes glasses	optician
a person who treats diseases of the feet	chiropodist
a person who studies the human mind	psychologist
a person who prepares and sells medicines	pharmacist
a person who designs buildings	architect
a person who writes the story of a person's life	biographer
a person who writes a story of his own life	autobiographer
a person who studies the weather	meteorologist
a person who is an expert in law	jurist

5.One Word for the Study of a Subject

Phrase or definition	One word
the study of the origin of words	etymology
the study of ancient societies from their remains	archaeology
the study of living things	biology
the study of the earth	geology
the study of the human mind	psychology
the study of birds	ornithology
the study of insects	entomology
the study of handwriting	graphology
the study of coins and medals	numismatics
the study of the stars and planets	astronomy
the study of human society	sociology
the study of weather	meteorology
the study of the structure of the body	anatomy
the study of diseases	pathology
the study of heredity	genetics
the study of the relation between living things and their environment	ecology
the study of ancient writings and inscriptions	epigraphy
the study of the sounds of language	phonetics

6.One Word for Government and Rule

Phrase or definition	One word
government by the people	democracy
government by one person with absolute power	autocracy
government by a small group	oligarchy
government by the rich	plutocracy
government by religious leaders	theocracy
government by the best-born class	aristocracy
government by a king or queen	monarchy
government by officials who are not elected	bureaucracy
absence of government	anarchy
government by one person who is ruthless	tyranny
a state ruled by a president	republic

7.One Word for Killing

Phrase or definition	One word
the killing of a king	regicide
the killing of a father	patricide
the killing of a mother	matricide
the killing of a brother	fratricide
the killing of a sister	sororicide
the killing of a wife	uxoricide
the killing of oneself	suicide
the killing of a baby	infanticide
the killing of a whole race or people	genocide
a substance that kills insects	insecticide
a substance that kills weeds	herbicide
a substance that kills germs	germicide

8.One Word for Fears and Strong Urges

Phrase or definition	One word
fear of heights	acrophobia
fear of open spaces	agoraphobia
fear of closed spaces	claustrophobia
fear of water	hydrophobia
fear of foreigners or strangers	xenophobia
fear of spiders	arachnophobia
fear of fire	pyrophobia
fear of the dark	nyctophobia
fear of cats	ailurophobia
fear of dogs	cynophobia
fear of crowds	ochlophobia
an irresistible urge to steal	kleptomania
an irresistible urge to set things on fire	pyromania
an extreme fondness for books	bibliomania

9.One Word for a Place

Phrase or definition	One word
a place where birds are kept	aviary
a place where bees are kept	apiary
a place where fish are kept	aquarium
a place where the dead are buried	cemetery
a place where coins are made	mint
a place where aeroplanes are kept	hangar
a place where medicines are sold	pharmacy
a place where books are kept	library
a place where orphans live	orphanage
a place where soldiers live	barracks
a place where monks live	monastery
a place where nuns live	convent
a place where objects of art or history are shown	museum
a place where animals are killed for food	slaughterhouse
a place where wild animals are kept for display	zoo
a place where bread is baked	bakery
a place where scientific experiments are done	laboratory
a place where the stars are observed	observatory
a place where clothes are washed	laundry
a place of safety	refuge
a room where food is stored	pantry
a place where criminals are kept	prison
a building for the storage of grain	granary
a place where plants are grown under glass	greenhouse

10.One Word for a Thing or a Quality

Phrase or definition	One word
that which cannot be avoided	inevitable
that which cannot be heard	inaudible
that which cannot be seen	invisible
that which cannot be believed	incredible
that which cannot be read	illegible
that which cannot be cured	incurable
that which cannot be touched	intangible
that which cannot be explained	inexplicable
that which cannot be defeated	invincible
that which cannot be corrected	incorrigible
that which cannot be satisfied	insatiable
that which can be eaten	edible
that which cannot be eaten	inedible
that which is no longer in use	obsolete
that which happens every year	annual
that which happens twice a year	biannual
that which happens every two years	biennial
that which lasts for ever	eternal
that which is possible to do	feasible
that which is found everywhere	ubiquitous
that which has power over all	omnipotent
that which knows everything	omniscient
that which is present everywhere	omnipresent
that which is done by choice	voluntary
that which must be done	compulsory
that which is easily broken	fragile
that which is difficult to understand	abstruse
that which cannot be pleased	fastidious
that which is open to two meanings	ambiguous
that which is lasting only for a short time	ephemeral
that which is difficult to find	elusive
that which is not clear in meaning	vague

11.One Word for an Action, Speech or Writing

Phrase or definition	One word
to give up the throne	abdicate
to give up a job or position	resign
to put to death by order of the law	execute
to run away secretly to get married	elope
to move from one place to another with the seasons	migrate
to make something less severe	mitigate
to speak ill of a person (spoken)	slander
to publish false statements about a person (written)	libel
to do away with something completely	abolish
to leave one's country to settle elsewhere	emigrate
to go in secret without permission	abscond
to speak without preparation	improvise
to pay back money that has been spent	reimburse
to cut off a part of the body	amputate
a speech delivered without preparation	extempore
a speech made by one actor alone on the stage	soliloquy
a speech in praise of a person	eulogy
a poem of mourning for the dead	elegy
a book of maps	atlas
a collection of poems or writings	anthology
a list of books	bibliography
a story of a person's life written by that person	autobiography
a story of a person's life written by another	biography
a statement that seems to contradict itself but may be true	paradox
a name used by a writer instead of his real name	pseudonym
a writer or author who is not named	anonymous
a word that has the opposite meaning	antonym
a word that has a similar meaning	synonym
a word that sounds like another but differs in meaning	homophone

12.Other Useful One-Word Substitutes

Phrase or definition	One word
a medicine that cures all diseases	panacea
a medicine that works against poison	antidote
an imaginary perfect place	utopia
an imaginary society where life is terrible	dystopia
having one wife or husband at a time	monogamy
having more than one wife or husband at a time	polygamy
having two wives or husbands at the same time	bigamy
a game in which neither side wins	draw
an official ban on trade with a country	embargo
untidy, hard-to-read handwriting	scrawl
an official count of the population	census
a gathering of people to listen to a talk	audience
a group of people who sing together	choir
a group of ships	fleet
a short, clever saying	aphorism
a rule that is accepted without proof	axiom
the right to vote	franchise
the act of looking back on the past	retrospect

13.Using One-Word Substitutes in Sentences

Learn each word in a sentence, so that you remember both the meaning and the way to use it.

Word	Example sentence
bibliophile	The bibliophile spent every weekend in second-hand bookshops.
philanthropist	The philanthropist donated a library to the town.
recluse	After her retirement she became a recluse.
polyglot	The guide was a polyglot who spoke six languages.
amateur	He is an amateur astronomer who studies the sky every night.
insolvent	The company was declared insolvent after the audit.
abdicate	The king decided to abdicate in favour of his son.
mitigate	Planting trees can mitigate the effects of pollution.
elope	The couple chose to elope rather than face a large wedding.
inevitable	With so little preparation, failure was inevitable.
ubiquitous	Mobile phones are now ubiquitous in cities.
ephemeral	The beauty of the blossom is ephemeral.
eulogy	His friend delivered a moving eulogy at the funeral.
paradox	It is a paradox that silence can be deafening.
pseudonym	The author published her novels under a pseudonym.
obsolete	The old typewriter is now obsolete.
abolish	Parliament voted to abolish the unfair tax.
anonymous	The poem was written by an anonymous writer.
antidote	The doctor administered the antidote immediately.
utopia	The writer imagined a utopia without poverty.

14.Commonly Confused One-Word Substitutes

Pair	Difference
emigrant / immigrant	An emigrant leaves a country; an immigrant arrives in a country.
biannual / biennial	Biannual means twice a year; biennial means every two years.
sceptic / cynic	A sceptic doubts claims until there is proof; a cynic believes that people act only from selfish motives.
atheist / agnostic	An atheist does not believe in God; an agnostic says it is impossible to know.
ascetic / aesthetic	Ascetic means strict self-denial; aesthetic relates to beauty and art.
libel / slander	Libel is a written false statement; slander is a spoken one.
biography / autobiography	A biography is written by another person; an autobiography is written by the person himself or herself.
bibliophile / bibliographer	A bibliophile loves books; a bibliographer lists and describes books.
amateur / novice	An amateur does something for love, not money; a novice is a beginner.
monarchy / oligarchy	Monarchy is rule by one king or queen; oligarchy is rule by a few.

15.Common Mistakes with One-Word Substitution

Mistake	Correct	Why
bibliophobe (for a book lover)	bibliophile	-phile means love; -phobe means fear.
immigrant (for someone leaving)	emigrant	Emigrate means to leave.
aesthetic (for self-denial)	ascetic	The two words sound alike but differ in meaning.
patricide (for killing a mother)	matricide	Pater means father and mater means mother in Latin.
unhearable	inaudible	Use the standard Latin-based word.
claustrophobia (for fear of open spaces)	agoraphobia	Agora was the open marketplace of ancient Greece.
bilingual (for a person who knows many languages)	polyglot	Bilingual means two languages; polyglot means many.
regicide (for killing a brother)	fratricide	Frater means brother in Latin.

Key points to remember

One-word substitution replaces a phrase with a single word of the same meaning.
Most substitutes come from Greek and Latin, so learn the word parts: phil-, -phobia, -cide, -ology, -cracy.
Learn each word with its meaning and a sentence of your own.
Watch for similar-looking pairs such as emigrant and immigrant, or biannual and biennial.
In an examination, write only one word as the answer, with correct spelling.

For teachers and parents

Activity: give students a list of ten phrases and ask them to write the one-word substitute, then to check the answers with a partner and use five words in sentences. A matching game with phrase cards and word cards works well for younger students. For older students, ask them to build their own phrases for words made from the same word parts.

Please note: this guide uses British spelling. Some substitutes have more than one accepted answer (for example, bureaucracy and officialdom), and only the most common are shown.

Where These Facts Come From

Cambridge DictionaryDefinitions and word information
British Council LearnEnglishFree vocabulary lessons
Oxford Learner's DictionariesDefinitions and word origins