The way a living creature behaves or acts.
* 2014 , A teacher, "
- She can't stop the strange behaviour because she has OCD (obsessive-compulsive disorder).
Choosing a primary school: a teacher's guide for parents", The Guardian , 23 September 2014:
The way a device or system operates.
- Teachers will probably be on their best behaviour for your visit – but don't be upset if they don't even notice you; they've got enough going on.
* Adjectives often applied to "behaviour" include: human, animal, physical, chemical, mechanical, electrical, organizational, corporate, social, collective, parental, interpersonal, sexual, criminal, appropriate, inappropriate, correct, incorrect, right, wrong, good, bad, acceptable, unacceptable, poor, ethical, unethical, moral, immoral, responsible, irresponsible, normal, odd, deviant, abnormal, violent, abusive, aggressive, offensive, defensive, rude, stupid, undesirable, verbal, nonverbal, learned, professional, unprofessional, adaptive, compulsive, questionable, assertive, disgusting, self-destructive.
* human behaviour
Etiquette (always plural in this sense).