1. Slang to steal (usually something of little value); pilfer
2. Slang to be an informer; tattle (on)
3. Slang an informer: also ˈsnitcher
Webster’s New World College Dictionary, Fourth Edition, compiled by the
editors of Webster’s New World Dictionaries. Copyright © 2010 by Houghton
Mifflin Harcourt. Published by Houghton Mifflin Harcourt. All rights reserved.
Word origin of 'snitch'< 18th-c. thieves' slang: orig. sense “a nose”