It is sometimes desirable to express the idea of a phrase or a group of words by using a single word:
- A child born after the death of its father – Posthumous
- A child born of parents who were not married – Illegitimate
- A child whose parents are dead – Orphan
- A gathering of worshippers – Congregation
- A hundred years – Century
- A man who remains unmarried – Bachelor
- A man whose wife is dead – Widower
- A person indifferent to both pleasure and pain – Stoic
- A person trained for competing in physical exercises and outdoor games – Athlete
- A person who always looks at the bright side of things – Optimist
- A person who always looks at the dark side of things – Pessimist
- A person who brings in goods from a foreign country – Importer
- A person who can use both hands with equal ease – Ambidextrous
- A person who comes as a settler into another country – Immigrant
- A person who does no work and lives on others – Drone
- A person who gets goods secretly and illegally into or out of a country – Smuggler
- A person who goes away from one’s own country to another to settle there – Emigrant
- A person who helps others, especially those who are poor or in trouble – Philanthropist
- A person who is a great lover of his country – Patriot
- A person who is sent to preach his religion, especially among people who are ignorant of it – Missionary
- A person who loves wealth for its own sake and is not inclined to spend it -Miser
- A person who represents his country’s economic, political and other interests in another country – Ambassador
- A person who sends goods to another country – Exporter
- A person who smuggles alcoholic liquor or sells it illegally – Bootlegger
- A person who spends extravagantly – Spendthrift
- A person who visits other countries for pleasure – Tourist
- A person who writes the life of another person – Biographer
- A place where bees are kept – Apiary
- A place where birds are kept – Aviary
- A plant or animal that draws sustenance from another – Parasite
- A traveller through outer space – Astronaut
- A woman who remains unmarried – Spinster
- A woman whose husband is dead – Widow
- Aircraft with two pairs of wings, one above the other – Biplane
- Allowing light to pass through, so that objects behind can be distinctly seen – Transparent
- An artificial pond or tank for keeping and showing living fish – Aquarium
- An operation performed on a dead body to find the cause of death – Postmortem
- Custom of having more than one husband at the same time – Polyandry
- Custom of having more than one wife at the same time – Polygamy
- Difficult or impossible to read – Illegible
- Fit to be eaten – Edible
- Going back from the reach of memory – Immemorial
- Government by nobles – Autocracy
- Government by officials – Bureaucracy
- Government carried on by the people or its elected representatives – Republic
- Government of the people, for the people and by the people – Democracy
- Grounds of a school, or university, where the main buildings are located – Campus
- Group of military operations with a set purpose, usually in one area – Campaign
- Having two wives or husbands living – Bigamy
- Helping neither side in war or quarrel – Neutral
- Incapable of making mistakes or doing wrong – Infallible
- Life history of a person written by another – Biography
- Life story of a person written by himself – Autobiography
- List of the days, weeks, months, of a particular year – Calendar
- Not favouring one more than another – Impartial
- Not yet fully developed – Immature
- Official in charge of a museum – Curator
- One who abstains from alcoholic drinks – Teetotaler
- One who believes implicitly in fate – Fatalist
- One who collects postage-stamps – Philatelist
- One who does not believe in the existence of God – Atheist
- One who goes on a journey to a holy place – Pilgrim
- One who is all-powerful – Omnipotent
- One who is present everywhere – Omnipresent
- One who is unable to pay one’s debts – Insolvent; bankrupt
- One who knows everything – Omniscient
- One who plays a game for pleasure and not professionally – Amateur
- One who studies the science of the sun, moon, stars, and planets – Astronomer
- Onewho cannot be elected or selected under the rules – Ineligible
- Person with no belief in religion (especially in what it is considered to be the true religion) – Infidel
- Practice of being married to only one person at a time – Monogamy
- Science of life and living things- Biology
- Soldiers who fight on horseback – Cavalry
- Sudden happening which makes quick action necessary – Emergency
- That can be spread by means of germs carried in the atmosphere or in water – Infectious
- That can be spread by touch – Contagious
- That cannot be seen through – Opaque
- That may be easily set on fire – Inflammable
- That which can he easily be understood – Intelligible
- That which cannot be approached – Inaccessible
- That which cannot be believed – Incredible
- That which cannot be blotted out or effaced – Indelible
- That which cannot be conquered – Invincible
- That which cannot be destroyed – Indestructible
- That which cannot be divided – Indivisible
- That which cannot be done without – Indispensable
- That which cannot be explained – Inexplicable
- That which cannot be heard – Inaudible
- That which cannot be perceived by the senses – Imperceptible
- That which cannot be recalled or altered – Irrevocable
- That which cannot be seen – Invisible
- That which cannot be solved – Insolvable
- That which is sure to happen – Inevitable
- That which makes it difficult to recognize the presence or real nature of something – Camouflage
- The act of killing oneself – Suicide
- The dead body of a human being – Corpse
- The dead body of an animal – Carcass
- The want of government in a country – Anarchy
- Unable to read or write – Illiterate
- Yearly return of the date of an event – Anniversary