A polygamist is a person who has more than one spouse, such as a polygamist who has three wives and 15 children.
Having more than one spouse, a polygamist is a busy person. Polygamist comes from the Greek: poly- means "many" and gamos means "marriage." So by definition, a polygamist can be a man with multiple wives or a woman with multiple husbands. The thing to remember is that the marriages are on-going. A person who gets a divorce and is later remarried is not a polygamist.