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 policy applies solely to LSA's substantial first-year cohort, drawing parallels with practices at institutions like MIT and Caltech and past COVID-era adjustments. — Michael T. Nietzel, Forbes.com, 6 Aug. 2026

The adults in the new research are from the Atherosclerosis Risk in Communities cohort study, which has followed nearly 15,800 adults from four communities in the United States since the late 1980s, when participants were between ages 45 and 65. — Kristen Rogers, CNN Money, 5 Aug. 2026

So, with an existing cohort of fans, a recent expansion, and a community-hub-cum-beading-studio in DUMBO, what does success look like for the future? — Madeline Hirsch, InStyle, 5 Aug. 2026

Kirkman was part of a summer cohort alongside other Atlanta fathers. — La'tasha Givens, CBS News, 5 Aug. 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.