1) Being a snitch 2) Disclosure 3) Informing 4) Revealing 5) Revelation 6) Selling out 1) Informing 
• (n.) The conduct or practices of one who rats. See Rat, v. i., 1. • (p. pr. & vb. n.) of Rat • (v. i.) The low sport of setting a dog upon rats confined in a pit to see how many he will kill in a given time.
Rat'ting (răt'tĭng) noun 1. The conduct or practices of one who rats. See Rat , intransitive verb , 1. Sydney Smith. 2. The low sport of setting a dog upon rats confined in a pit to see how many he will kill in a given time. 
noun to furnish incriminating evidence to an officer of the law (usually in return for favors)