What does "complaint" mean?

Additional senses

1. 2.Cause or subject of complaint or murmuring. The poverty of the clergy in England hath been the complaint of all who wish well to the church. Swift.
2. 3.An ailment or disease of the body. One in a complaint of his bowels. Arbuthnot.
3. 4.(Law) A formal allegation or charge against a party made or presented to the appropriate court or officer, as for a wrong done or a crime committed (in the latter case, generally under oath); an information; accusation; the initial bill in proceedings in equity.