One who actively assists, defends, pleads, prosecutes, speaks, writes, or otherwise supports the cause of another. 2 n. A lawyer. 3 v. To speak, write, or otherwise support a cause by argument. aff'd abbr. Affirmed. aff'g abbr. Affirming. n. affiant One who makes and subscribes to an affidavit. n.A affidavit voluntary and written ex parte statement of facts signed and the truth of its content affirmed or sworn to affirmative action by the declarant before a notary public or another officer au...