co·hort | \ˈkō-ˌhȯrt \

Definition of cohort 

1 : companion, colleague a few of their … cohorts decided to form a company— Burt Hochberg

2a : 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

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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 via French 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.

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

Paddington 2 is one of the best movies of the year, period, and now the similarly-beloved Winnie the Pooh and his iconic cohorts Eeyore, Piglet, and the rest, are getting a live-action update in Christopher Robin, coming out later this year. Tom Philip, GQ, "Winnie the Pooh Gets a Glorious Reboot in the Christopher Robin Trailer," 25 May 2018 Actor Jack Black and his musical cohort Kyle Gass are bringing their act to Philly’s Fillmore on Nov. 8 as part of their first tour in five years. Nick Vadala,, "Jack Black's Tenacious D coming to Philly's Fillmore this fall," 15 May 2018 The researchers ran computer simulations on a hypothetical cohort of over 360,000 women to test the efficacy and costs of risk-stratified screening. Orly Nadell Farber, STAT, "New approach to breast cancer screening — tailoring guidelines for each patient — may save lives and money, study says," 5 July 2018 But a small cohort of followers love Rodríguez for his hard line on drug cartels—for which he has nearly been assassinated twice. Ciara Nugent, Time, "Your Complete Guide to Mexico's 2018 Elections," 29 June 2018 Her charges are a small cohort of androgynous juveniles, who bear the immature reproductive tissues of both sexes. Katherine J. Wu, Smithsonian, "Alternatives to Heterosexual Pairings, Brought to You By Non-Human Animals," 28 June 2018 In truth, millennials aren't a uniform cohort of feckless young people., "Not An Entitled Millennial: How 4 Young Women Support Their Whole Families," 27 June 2018 In other news, colleges around the country, including some close by, are preparing for a new cohort this fall: students with intellectual disabilities. Aubrey Nagle,, "Opioid deaths reveal precarious recoveries, more school money in Pa. budget | Morning Newsletter," 25 June 2018 American men experienced the largest decline of any OECD country, and American women were the only female cohort in the entire OECD whose workforce participation fell. William A. Galston, WSJ, "Can America Grow Like It Used To?," 29 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cohort.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of cohort

15th century, in the meaning defined at sense 2c

History and Etymology for cohort

Middle English, from Latin cohort-, cohors — more at court

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Statistics for cohort

Last Updated

18 Oct 2018

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Time Traveler for cohort

The first known use of cohort was in the 15th century

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More Definitions for cohort



English Language Learners Definition of cohort

: a friend or companion

: a group of people used in a study who have something (such as age or social class) in common


co·hort | \ˈkō-ˌhȯ(ə)rt \

Medical Definition of cohort 

: 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

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