1 a the way one conducts oneself; manners. b the treatment of others; moral conduct.
2 the way in which a ship, machine, chemical substance, etc., acts or works.
3 Psychol. the response (of a person, animal, etc.) to a stimulus.
Phrases and idioms:
behaviour therapy the treatment of neurotic symptoms by training the patient's reactions (see BEHAVIOURISM). be on one's good (or best) behaviour behave well when being observed.
Etymology: BEHAVE after demeanour and obs. haviour f. have
Useful english dictionary. 2012.