corollary

American  

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

noun

corollaries plural

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.

---

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

---

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.

---

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

This, as Mr. Ferguson notes, echoes Theodore Roosevelt’s so-called Roosevelt Corollary to the Monroe Doctrine, first set forth in 1904.

From The Wall Street Journal • Dec. 8, 2025

Corollary to the “monster,” more passive, is the “stain”: some ugliness coloring someone’s life that you don’t want to know, that nonetheless spreads and can ruin perception of his or her work.

From New York Times • Apr. 23, 2023

Corollary: is that the barometer of a successful season?

From Seattle Times • Jun. 3, 2022

In the first quarter of the twentieth century, that Roosevelt Corollary would be used to justify U.S. occupations of Cuba, the Dominican Republic, Haiti, and Nicaragua.

From Salon • Jan. 28, 2021

Corollary may be illustrated by the example of a sick and a healthy man.

From Ethics by Spinoza, Benedictus de

Related Words

• analogy
• upshot