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
• 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

From Traditionalists to Generation-Z, each cohort brings distinct experiences, competencies and expectations shaped by their social, economic and technological environments. —Britton Bloch, Forbes.com, 4 Aug. 2025

The older age cohort, which includes ages 61 to 79, showed signs of potential digital addiction despite stereotypes that phone and social media overuse mainly impacts younger age groups. —Suzanne Blake, MSNBC Newsweek, 1 Aug. 2025

More than 900 scientists are part of the DESI collaboration; getting that large dark-energy cohort mobilized around the most fruitful ideas, as DESI’s results may, could prevent them from simply spinning their wheels. —Sarah Scoles, JSTOR Daily, 31 July 2025

The first cohort kept its location private for safety reasons. —Jon-Michael Banks, Kansas City Star, 30 July 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

Podcast

Get Word of the Day delivered to your inbox!

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.