Do you know ghouls from goblins and ghosts?
late 14c., "lamentation, grief," from Old French complainte (12c.) "complaint, lament," noun use of fem. past participle of complaindre (see complain). Meaning "bodily ailment" is from 1705 (often in U.S. colloquial use generalized as complaints).
in law, the plaintiff's initial pleading, corresponding to the libel in admiralty, the bill in equity, and the claim in civil law. The complaint, called in common law a declaration, consists of a title, a statement showing venue or jurisdiction, one or more counts containing a brief formal exposition of facts giving rise to the claim asserted, and a demand for relief. Thus, it informs the defendant of the plaintiff's claim and initiates the pretrial process of narrowing the case to one or more sharply defined issues of law or fact. In common law and under early procedural codes, the task of defining the issues was performed solely by the pleadings, but modern procedural systems have added pretrial conferences and deposition and discovery procedures for this purpose.