corollary

American  

[kawr-uh-ler-ee, kor-, kuh-rol-uh-ree] / ˈkɔr əˌlɛr i, ˈkɒr-, kəˈrɒl ə ri /

noun

plural

corollaries

1. Mathematics. a proposition that is incidentally proved in proving another proposition.

2. an immediate consequence or easily drawn conclusion.

3. a natural consequence or result.

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corollary British  

/ kəˈrɒlərɪ /

noun

1. a proposition that follows directly from the proof of another proposition

2. an obvious deduction

3. a natural consequence or result

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adjective

1. consequent or resultant

corollary Scientific  

/ kôr′ə-lĕr′ē /

1. A statement that follows with little or no proof required from an already proven statement. For example, it is a theorem in geometry that the angles opposite two congruent sides of a triangle are also congruent. A corollary to that statement is that an equilateral triangle is also equiangular.

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Etymology

Origin of corollary

1325–75; Middle English < Late Latin corollārium corollary, in Latin: money paid for a garland, a gift, gratuity. See corolla, -ary

Explanation

Corollary describes a result that is the natural consequence of something else. You could say that your renewed love of books is a corollary to the recent arrival of a book store in your neighborhood. The noun corollary describes an action's consequence. For example, a good grade on an exam is a corollary of studying for long hours. The word is often seen with the prepositions "to" or "of," as in "a corollary to fortune is fame." Math enthusiasts may already be familiar with the word corollary, which can be used more formally to describe a new proof or proposition that follows naturally from an established one.

Example Sentences

The corollary is lower sales, thinner margins and smaller corporate profits.

From Barron's • Feb. 20, 2026

A corollary of Erb’s investment lesson is that when an asset that previously deviated from fair value eventually returns towards fair value, there is no guarantee that it will stop once it gets there.

From MarketWatch • Feb. 10, 2026

The increasing opacity of these financing structures has led to a corollary collapse in collateral verification.

From The Wall Street Journal • Oct. 27, 2025

Just to put my Captain Obvious pants on for a minute, the corollary to everything you just said is that he’s also decided he’s going to tell us what the truth is, right?

From Slate • Oct. 17, 2025

The high rate of turnover had the corollary benefit of keeping to a minimum the number of individuals who understood the building’s secrets.

From "The Devil in the White City" by Erik Larson

Related Words

• analogy
• upshot