What is the meaning of snitch?

noun

• Someone acting as an informer or decoy for the police.
  • synonyms: fink, snitcher, stoolpigeon, stool pigeon, stoolie, sneak, sneaker, canary

verb

• Take by theft.
  • usage: "Someone snitched my wallet"
  • synonyms: hook, thieve, cop, knock off, glom
• Give away information about somebody.
  • usage: "He told on his classmate who had cheated on the exam"
  • synonyms: denounce, tell on, betray, give away, rat, grass, shit, shop, stag