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

In an interview late last year with infectious disease news site Contagion Live, Pfizer’s head of discovery and early development Charlotte Allerton was hopeful this new antiviral iteration could help a significant cohort of vulnerable patients who were previously unable to take Paxlovid. —Rich Haridy, New Atlas, 18 Mar. 2025

After an incredible 2024 and a roaring start to 2025, the cybersecurity cohort has been out of favor lately. —Paulina Likos, CNBC, 18 Mar. 2025

The first cohort of institutions will receive $40,000 in grants for transformative projects that benefit their campuses and surrounding communities. —Marybeth Gasman, Forbes, 18 Mar. 2025

At the Clemente, located in a historic neo-Gothic building dating to 1897, visuals arts in the galleries butt against a robust cohort of various theater groups, alongside several artist studios. —Maximilíano Durón, ARTnews.com, 18 Mar. 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.