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

Cordes’s cohort of scientists helped to show that the devastation of oil spills goes far beyond our coasts, where birds and fish are the most visible victims. —Jeffrey Marlow, New Yorker, 5 Apr. 2026

The internship’s first cohort runs from June 1 to June 26, and the second runs from July 6 to July 31. —Maya Wilkins, Chicago Tribune, 3 Apr. 2026

And although the younger cohort was giving its purchases a fair amount of thought, the survey, which recorded responses from 1,000 shoppers across the US, also found that both Gen Z and millennials are 50% more likely to spend more in the future versus older generations. —Jeena Sharma, Fortune, 1 Apr. 2026

Surrounding Fox’s keen central performance are a number of skilled and sensitive portrayals, in particular Swoosie Kurtz, as a lonely co-worker who is genuinely concerned about her young cohort’s well-being. —Duane Byrge, HollywoodReporter, 1 Apr. 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

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.