n. A person who tells authorities about improper or illegal activity.
the GNU version of the Collaborative International Dictionary of English
n. One who informs, animates, or inspires.
n. One who informs, or imparts knowledge or news.
n. One who informs a magistrate of violations of law; one who informs against another for violation of some law or penal statute.
The Century Dictionary and Cyclopedia
n. One who informs or animates.
n. One who imparts intelligence or gives information; an informant.
n. In law, one who communicates to a magistrate a knowledge of a violation of law; a person who lays an information against or prosecutes in the courts one who offends against the law or any penal statute.
n. Hence One who makes a business of informing against others; a mischief-maker.
n.Synonyms Informant, Informer. See informant.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. one who reveals confidential information in return for money
Word Usage
"To turn these facts into "Socialist icon who became an informer" is itself (sorry, but it's irresistible)"