cohort

noun

co·​hort ˈkō-ˌhȯrt 

1

: companion, colleague

… a few of their … cohorts decided to form a company …

—Burt Hochberg

2

a

: band, group

a cohort of supporters

b

: a group of individuals having a statistical factor (such as age or class membership) in common in a demographic study

a cohort of premedical students

the cohort of people born in the 1980s

c

: one of 10 divisions of an ancient Roman legion

d

: a group of warriors or soldiers

Did you know?

In ancient times, a cohort was a military unit, one of ten divisions in a Roman legion. The term passed into English in the 15th century, when it was used in translations and writings about Roman history. Once cohort became established in our language, its meaning was extended, first to refer to any body of troops, then to any group of individuals with something in common, and later to a single companion. Some usage commentators have objected to this last sense because it can be hard to tell whether the plural refers to different individuals or different groups. The "companion" sense is well established in standard use, however, and its meaning is clear enough in such sentences as "her cohorts came along with her to the game."

Synonyms of cohort

• associate
• colleague
• peer
• fellow
• friend
• buddy
• classmate
• accomplice

Examples of cohort in a Sentence

The police arrested the gang's leader and his cohorts.

Depression was a common problem for people in that age cohort.

Recent Examples on the Web

Parallel societies in certain urban areas and rising violent crime statistics linked to some migrant cohorts in countries such as Sweden and Germany led to the dramatic rise of populist and patriotic parties across the continent, from France to Italy to the Netherlands. —Daniel Ross Goodman, The Washington Examiner, 9 Jan. 2026

McAfee's usual cohort — including AJ Hawk, Darius Butler, Connor Campbell, Ty Schmit and Tone Digs — will also be part of the broadcasts. —Wesley Stenzel, Entertainment Weekly, 8 Jan. 2026

Under a plan officials are considering, two elementary schools would close, the district's virtual academy would shut down for K-8 students and three additional schools would move their seventh and eight grade cohort to a nearby high school by 2028. —Erick Trevino, AZCentral.com, 8 Jan. 2026

But the cohort has since cooled its buying, and the attacks slowed. —Bloomberg, Mercury News, 8 Jan. 2026

Word History

Etymology

Middle English, from Latin cohort-, cohors — more at court

First Known Use

15th century, in the meaning defined at sense 2c

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Kids Definition

cohort

noun

co·​hort ˈkō-ˌhȯrt 

1

a

: one of 10 divisions of an ancient Roman legion

b

: a group of warriors or followers

2

: companion sense 1, accomplice

Medical Definition

cohort

noun

co·​hort ˈkō-ˌhȯ(ə)rt 

: a group of individuals having a statistical factor (as age or risk) in common

the population consisted of two cohorts: 204 clearly exposed and 163 not exposed

—R. R. Suskind et al.