1. the way a person or animal acts or conducts themselves
Usage: British spelling; American spelling is 'behavior'
2. the way something functions or operates under specific conditions
Usage: technical or scientific contexts

Examples

• The teacher praised the student’s excellent behaviour in class.
• His aggressive behaviour toward his colleagues was unacceptable.
• The dog’s behaviour improved after training.
• Scientists studied the behaviour of particles under extreme temperatures.
• Her polite behaviour made a good impression on everyone.
• The software’s behaviour was unpredictable after the update.
• Children often model their parents’ behaviour.