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 (as in “a cohort of law students” or “a cohort of people who were born in the same year”), and later to a single companion. Some writers on usage 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

The survey also found that this cohort of young high-net-worth collectors is more likely to purchase directly from artists rather than dealers and auction houses. — News Desk, Artforum, 8 Oct. 2026

Martínez will travel to Spain to participate early next year, while a participant from Málaga Talent’s 2027 cohort will come to Vancouver for Catalyst later that year. — Katherine Brodsky, Variety, 8 Oct. 2026

Newsom, First Partner Jennifer Siebel Newsom and Chief Service Officer Josh Fryday — who oversees GO-SERVE — appeared Wednesday at a ceremony welcoming 10,000 new California Volunteers for its 2026-2027 cohort. — Lia Russell, Sacbee.com, 8 Oct. 2026

By demographic cohort, younger consumers are leading the resale charge. — Arthur Zaczkiewicz, Footwear News, 8 Oct. 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.