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

The 2025 New York City Marathon had a record 59,226 participants, nearly 11,000 of which were 25- to 29-year-olds, constituting the largest cohort of runners at nearly 25%. —Sasha Rogelberg, Fortune, 6 Feb. 2026

While appearing on The Dan Patrick Show on Friday, the former Oklahoma Sooner was asked about whether his cohort and signature handshake partner will be returning to Dallas in 2026. —Sportsday Staff, Dallas Morning News, 6 Feb. 2026

But since his 2016 debut, Bad Bunny has emerged as the leader of a new cohort of barrier-breaking artists, among them Karol G, J Balvin, Anitta and Peso Pluma, who are globalizing the genre and redefining crossover appeal with their fierce cultural pride. —Edward Segarra, USA Today, 5 Feb. 2026

If all goes as planned, the first cohort of six community culinary students will start mid-year and finish about six months later. —Meg Wingerter, Denver Post, 5 Feb. 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.