To complain means to express unhappiness or dissatisfaction with something, often because it's not right or fair.
We all do it sometimes - we let our friends know when a situation is bothering us. Maybe you were stuck in traffic and got late for work, so you tell your coworker about the terrible congestion on the highway. Or perhaps someone didn't show up for a planned meeting, so you send an email expressing your frustration. Complaining can be a way to share our feelings with others when we feel like something isn't going well or as it should.
To express feelings of pain, dissatisfaction, or resentment.
Example: Joe was always complaining about the noise made by his neighbours.
