be·​hav·​ior | \ bi-ˈhā-vyər How to pronounce behavior (audio) , bē-\

Definition of behavior

1 : the way in which someone conducts oneself or behaves (see behave sense 1) We were grateful for the gracious behavior of our hostess. The children were rewarded for good behavior. Be on your best behavior. also : an instance of such behavior unacceptable social behaviors
2a : the manner of conducting (see conduct entry 1 sense 2) oneself criminal behavior normal adolescent behavior
b : anything that an organism does involving action and response to stimulation
c : the response of an individual, group, or species to its environment They are studying the behavior of elephants in the wild.
3 : the way in which something functions or operates They tested the behavior of various metals under heat and pressure.

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Synonyms for behavior


actions, address, bearing, comportment, conduct, demeanor, deportment, geste (also gest) [archaic]

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Examples of behavior in a Sentence

I'm surprised by her bad behavior toward her friends. Students will be rewarded for good behavior. scientists studying the behavior of elephants An acceptable social behavior in one country may be unacceptable in another country. Doctors are trying to educate people about behaviors that can put them at increased risk for skin cancer. The experiment tested the behavior of various metals under heat and pressure.
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Recent Examples on the Web

By the end of the season, he's opted out of the system of loyalty that allowed his teammates to get away with their bad behavior. Elena Nicolaou,, "Is Charlie Saint Of 13 Reasons Why Just Another Toxic Athlete?," 24 Aug. 2019 In a move that mirrored something his character Tony Stark might do, Downey Jr. started his remarks by hilariously apologizing for some of his past behavior. Lauren Huff,, "Avengers: Endgame coming to Disney+ in December," 23 Aug. 2019 My trust in him is broken, and I’m devastated at his behavior. Abigail Van Buren, Twin Cities, "Dear Abby: Husband betrays wife’s trust by posting nude photos of her," 21 Aug. 2019 Victoria also mentioned a prior conversation between her and Blanton about drugs motivating his behavior. Kala Kachmar, The Courier-Journal, "Judge grants mistrial in case of accused cannibal Joseph Oberhansley," 21 Aug. 2019 Already, this species, which lives in the Americas along coastal waters, was a bit of a weird one, but some of their behaviors made them an easy—and interesting—study in how spider populations are affected by extreme weather events. John Wenz, Popular Mechanics, "Why Hurricanes Makes This Spider Even More Aggressive," 19 Aug. 2019 Unconvinced, Lindsay again concluded that firing was the proper discipline for Hill’s behavior. Julie Small, The Mercury News, "Ex-Richmond cop swapped sexually explicit texts with exploited teen while on duty," 15 Aug. 2019 The Surfrider Foundation also encourages fees instead of outright bans as the most effective way to incentivize consumers to change their behavior. Sarah Gibbens, National Geographic, "See the complicated landscape of plastic bans in the U.S.," 15 Aug. 2019 Qualified participants had to have been able to observe their kitty’s behavior for three or more hours a day. Jason Daley, Smithsonian, "Researchers Think They Know Why Cats Eat Grass," 12 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'behavior.' 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 behavior

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

History and Etymology for behavior

alteration of Middle English behavour, from behaven "to behave" + -our -or entry 2

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Statistics for behavior

Last Updated

27 Aug 2019

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Time Traveler for behavior

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

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More Definitions for behavior



English Language Learners Definition of behavior

: the way a person or animal acts or behaves
: the way something (such as a machine or substance) moves, functions, or reacts


be·​hav·​ior | \ bi-ˈhāv-yər How to pronounce behavior (audio) \

Kids Definition of behavior

1 : the manner in which a person acts Students are rewarded for good behavior.
2 : the whole activity of something and especially a living being Scientists observed the elephant's behavior.


variants: or chiefly British behaviour \ bi-​ˈhā-​vyər How to pronounce behaviour (audio) \

Medical Definition of behavior

1 : the manner of conducting oneself
2a : anything that an organism does involving action and response to stimulation
b : the response of an individual, group, or species to its environment

Other Words from behavior

behavioral or chiefly British behavioural \ -​vyə-​rəl How to pronounce behavioural (audio) \ adjective
behaviorally or chiefly British behaviourally \ -​rə-​lē How to pronounce behaviourally (audio) \ adverb

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More from Merriam-Webster on behavior

Thesaurus: All synonyms and antonyms for behavior

Spanish Central: Translation of behavior

Nglish: Translation of behavior for Spanish Speakers

Britannica English: Translation of behavior for Arabic Speakers

Comments on behavior

What made you want to look up behavior? Please tell us where you read or heard it (including the quote, if possible).


readily or continually undergoing change

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