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

• 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

Tactics will remain flexible to adapt to changing fire behavior and operational conditions. —Ca Wildfire Bot, Sacbee.com, 30 Aug. 2025

John Greenway, Managing Partner, founded the firm in 2017 to address abusive creditor behavior and the general lack of support for debtors, a philosophy that the company still follows. —Jason Phillips, USA Today, 29 Aug. 2025

Gallup and Korn Ferry research confirm that up to 80% of team engagement is shaped by leadership behavior. —Laurel Donnellan, Forbes.com, 29 Aug. 2025

Higher-income households had the highest percentage of retail refunds, at 5.3% of their purchases in 2025, according to a recent report by the Bank of America Institute that compared higher-, middle- and lower-income shopper return behavior. —Ana Teresa Solá, CNBC, 29 Aug. 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