Other forms: behaviors
Behaviour is the way a person acts. Good behaviour, bad behaviour, his behaviour was extraordinary.
It is uncountable in that sense and takes no article. The spelling splits: behaviour in British English, behavior in American, and the u also goes in behavioural. The word is not only about people — the behaviour of a material, the behaviour of a market, animal behaviour — and in science it is a neutral technical term. Note behave, the verb, which used on its own as an order means behave well: just behave, will you.
1nounbehaviorThe way somebody acts.
“His behaviour at the meeting was hard to explain.”
2nounanimalThe way an animal or a thing acts or works.
“The study looks at the behaviour of the material under heat.”
Too few real examples of this word to estimate which sense is commonest.
behavior is a way of acting.
Also accepted in games: behaviour, conduct
Behaviour is have with a be- prefix, meaning to bear or conduct oneself — the same idea as the reflexive verbs other European languages use for this. The -iour spelling was influenced by havior, an old word for possessions, which is why it looks French and is not.
Proto-Indo-European
*kap-
Old English
behabban
Middle English
behavoure
English, today
behavior
From Middle English behavoure, from und + behaven, from Old English behabban. From Middle English behavoure, behaver, from behaven (modern behave), morphologically equivalent to behave + -ior. The suffix was adopted in imitation of havour (modern haviour, havior), an etymologically unrelated word that was corrupted from Anglo‐Norman Anglo-Norman aveir and Old French Old French avoir (“property, wealth”) through false association with the native English verb have. The French term derives ultimately from Latin Latin habeō (“to have, hold”). Compare Scots havings (“behavior”), from have (“to behave”). Replaced ġebǣru.
Etymology from Wiktionary, CC BY-SA