behavior

noun

be·​hav·​ior bi-ˈhā-vyər 

bē-

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

2

a

: 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.

Synonyms of behavior

• actions
• demeanor
• attitude

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.

Recent Examples on the Web

Their behavior continues to strain ties with the royal family, which has no interest in being linked to the Sussexes’ business ventures. —Stephanie Nolasco , Ashley Papa, FOXNews.com, 25 Nov. 2025

Owners can provide training sessions, puzzle toys or give structured jobs, such as laundry, to keep their Australian shepherds mentally and physically stimulated, preventing boredom or destructive behavior. —Liz O'Connell, MSNBC Newsweek, 25 Nov. 2025

After the game, which the 49ers won 20-9, Jennings angrily blasted Moehrig’s behavior. —Sean Neumann, PEOPLE, 25 Nov. 2025

That was seditious behavior, that was a big deal. —Luke Barr, ABC News, 25 Nov. 2025

Word History

Etymology

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

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing behavior

• behavior modification
• behavior therapy
• cognitive behavior therapy
• for good behavior
• on one's best behavior
• on their best behavior

Rhymes for behavior

• behaviour
• havior
• savior
• saviour
• misbehavior
• misbehaviour

Kids Definition

behavior

noun

be·​hav·​ior bi-ˈhā-vyər 

1

: the way in which one conducts oneself

2

: the way in which something (as a machine) behaves

3

: anything that a living being does that involves action and response to stimulation

behavioral

-vyə-rəl 

adjective

Medical Definition

behavior

noun

be·​hav·​ior

variants or chiefly British behaviour

bi-ˈhā-vyər 

1

: the manner of conducting oneself

2

a

: anything that an organism does involving action and response to stimulation

b

: the response of an individual, group, or species to its environment

behavioral adjective

or chiefly British behavioural

-vyə-rəl 

behaviorally adverb

or chiefly British behaviourally

-rə-lē