What is the meaning of Complaint?

The act of complaining.

A grievance, problem, difficulty, or concern.

In a civil action, the first pleading of the plaintiff setting out the facts on which the claim is based.

In criminal law, the preliminary charge or accusation made by one person against another to the appropriate court or officer, usually a magistrate.

A bodily disorder or disease; the symptom of such a disorder.

Source: wiktionary.org