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

About half of the people in that 85-and-up cohort will need daily assistance to maintain their health and dignity, either from a skilled nursing home, an assisted living center or regular visits from an in-home caregiver, professional or family. —Andre Mouchard, Oc Register, 20 June 2025

Cannabis use significantly increased all-cause mortality and cardiovascular mortality in a cohort of patients who experienced a heart attack before age 50. —Angelica Stabile, FOXNews.com, 19 June 2025

Democrats have been losing support among this cohort for years: Among Latino voters without a college degree, support for Democrats plunged from 69% in 2012 to just 53% in 2024, according to Catalist, a progressive organization that analyzes precinct-level voting results. —David M. Drucker, Twin Cities, 18 June 2025

The Sacramento program will accept between 20–25 students in its first cohort, which runs from September 2025 to January 2026. —Cathie Anderson, Sacbee.com, 18 June 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.