To express dissatisfaction or annoyance about something. She complained about the noise coming from the construction site.
To state that something is wrong or not satisfactory. He complained to the manager about the poor service at the restaurant.
To make a formal accusation or initiate legal action against someone or something. The plaintiff complained that the contract had been breached.
To report or describe a symptom of illness or physical discomfort. Several passengers complained of nausea during the turbulent flight.