Other forms: behaves, behaved, behaving
To behave is to act in a particular way. A dog behaves well on the lead, a car behaves badly in the wet, and when a parent hisses 'behave' across a supermarket aisle, they mean act properly and stop it now.
On its own, behave means behave well: if you behave, we can stay for pudding. With an adverb it is neutral — behave badly, behave strangely, behave like an adult. Behave yourself is the fixed reflexive form, and you will hear it constantly from tired adults. Scientists use the word for things that have no manners at all: how a metal behaves under heat, how a market behaves after a crash. The noun is behaviour, spelled behavior in America, and you never behave someone — the verb takes no object except yourself.
1verbbehaveTo act in a particular way.~62%
“He behaves quite differently when his manager is in the room.”
synonyms: act, conduct yourself
2verbpoliteTo act in the polite, controlled way people expect.~15%
“Behave yourself at your grandmother's, and no elbows on the table.”
3verbsubstanceOf a substance, machine or system, to react in a particular way under particular conditions.~23%
“Glass behaves strangely when it is heated too quickly.”
Shares are an estimate: a language model read 13 sentences found in the wild and placed 13 of them on a sense — a count of our sample, not a measurement of English.
Behave is be- plus have, from Old English behabban, whose meanings were to surround, contain, hold back, restrain. Have there is closer to hold than to own. So behaving was holding yourself in, which is exactly what a parent still means by it.
Proto-Indo-European
*kap-
Old English
behabban
Middle English
behaven
English, today
behave
Built from
From Middle English behaven, from Old English behabban. From Middle English behaven, bihabben (“to restrain, behave”), from Old English behabban (“to surround, embrace, hold, contain, hold back, withhold, restrain”), from Proto-West Germanic bihabbjan, equivalent to be- + have. Cognate with Middle Low German behebben, behāven (“to receive, acquire, reach, keep”), Low German behebben (“to act, behave”), German behaben (“to behave”).
Etymology from Wiktionary, CC BY-SA