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

• associate
• companion
• compatriot
• compeer
• comrade
• crony
• fellow
• hobnobber
• mate
• running mate

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

These younger cohorts are dealing with student loan balances that seem to never go down. —Thomas G. Moukawsher, MSNBC Newsweek, 23 Apr. 2025

New polling also indicates the youngest cohort of eligible voters, those 18-21, may be swinging more significantly towards the GOP. —Elena Moore, NPR, 23 Apr. 2025

What’s more, there’s a growing cohort of influencers being shadowbanned or, worse, de-platformed. —Solo Ceesay, Rolling Stone, 22 Apr. 2025

Current systems segment customers into broad cohorts, but emerging AI capabilities will enable hyper-personalized experiences based on individual behavior patterns. —Jitender Jain, Forbes.com, 21 Apr. 2025

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.