"informer," 1785, probably from underworld slang meaning "the nose" (1700), which apparently developed from an earlier meaning "fillip on the nose" (1670s). Snitcher in same sense is from 1827.
snitch (v.)
1803, "to inform," from snitch (n.). Meaning "to steal, pilfer" is attested from 1904, perhaps a variant of snatch (v.). Related: Snitched; snitching.
例文
1. I managed to snitch abdul abdullah 's breakfast.
アブ?アードラを何とか手に入れようとした。
2.Lieutenant Colonel Frank Slade:But not a 6 snich .
フランク?スレイド大佐:しかし、密告者ではありません。
3.At the last moment,Harry caught the Snitch for 150 points.