One word substitution

One word substitution is replacing a phrase or a group of words with a single precise word that carries the same meaning — for example, “a person who eats everything” becomes omnivore. It is a test of vocabulary and precision: knowing the exact word instead of a long description.

Because precise vocabulary makes your English tighter and clearer, in writing and in speech. It is a common section in many English and competitive exams, and the underlying skill — recognising and recalling exact words — is what strong reading and writing rest on.

Omnivore. By contrast, a plant-eater is a herbivore and a meat-eater is a carnivore. The -vore root comes from the Latin for “to devour”.

Acrophobia. The suffix -phobia means an extreme or irrational fear, so most fears follow the same pattern: fear of water is hydrophobia, fear of enclosed spaces is claustrophobia.

Democracy. The suffix -cracy means rule or government: government by one is autocracy, by officials is bureaucracy, by the wealthy is plutocracy.

Regicide. The suffix -cide means killing: killing oneself is suicide, killing a brother is fratricide, killing a whole group is genocide.

Ornithology. The suffix -logy means the study of a subject: the study of insects is entomology, of the earth is geology, of the mind is psychology.

Learn the roots and suffixes rather than memorising words one by one. Once you know -cide = killing, -cracy = rule, -phobia = fear and -logy = study, you can decode and recall whole families of words at once. Group them by theme, and revise a small set daily rather than a long list once.

-cide comes from the Latin caedere, “to kill”. So any word ending in -cide is a kind of killing — suicide, homicide, pesticide (killing pests), regicide (killing a king).

Illiterate. The opposite — someone who can read and write — is literate, and the ability itself is literacy.

Aviary. A place for keeping bees is an apiary, and a place for keeping many animals for display is a menagerie.

All three describe what a creature eats: a herbivore eats plants, a carnivore eats meat, and an omnivore eats both. A person who chooses to eat no meat is usually called a vegetarian.

Inevitable. The prefix in- means “not”, so it literally means “not avoidable”. The same prefix gives incredible (not believable) and incorrigible (not correctable).

Bibliophile. The root biblio- means book and -phile means lover, so it is literally a book-lover.

Aim to master the common families first — the fears, the forms of government, the killings, the studies — which cover most of what you will meet. A working set of 150–250 covers the vast majority; beyond that, returns shrink, and wide reading picks up the rest naturally.

Not as a named task — the DET has no “one word substitution” section. But a wide, precise vocabulary is exactly what its vocabulary-heavy tasks reward: Read & Select asks you to recognise real words on sight, Fill in the Blanks rewards the exact word, and richer word choice lifts your Writing and Speaking. So this list is vocabulary-building that feeds the test, not a DET drill.