dry-snitch verb to betray or inform on someone either unintentionally or indirectly but intentionally US
[W]ho would happily drysnitch you off in the messhall if they saw you stealing an extra chop from the stainless-steel steamtables. — Clarence Cooper Jr, TheFarm, p. 27, 1967
— Maledicta, p. 264, Summer/Winter 1981: “By its slang, ye shall know it: the pessimism of prison life”