behaviour

Universal Words (BrE) (AmE behavior) noun 1 [U] the way that sb behaves, especially towards other people: good / bad behaviour * social / sexual / criminal behaviour * His behaviour towards her was becoming more and more aggressive. 2 [U,C] the way a person, an animal, a plant, a chemical, etc. behaves or functions in a particular situation: the behaviour of insects / dolphins / chromosomes * studying human and animal behaviour * (technical) to study learned behaviours and attitudes behavioural (BrE) (AmE behavioral ) adjective: children with behavioural difficulties * behavioural science (= the study of human behaviour) IDIOMS be on your best behaviour to behave in the most polite way you can