(legal) In a civil action, the first pleading of the plaintiff setting out the facts on which the claim is based; (legal) In criminal law, the preliminary charge or accusation made by one person against another to the appropriate court or officer, usually a magistrate. lunch times and Complaints are usually closed within 30 business days. Specifically, it the act of expressing dissent with the current or former state of something.       Why are Stratolaunch's engines so far forward? OOP implementation of Rock Paper Scissors game logic in Java. The main difference between complain and complaint is that complain is a verb whereas complaint is a noun.