[n] someone acting as an informer or decoy for the police
[n] someone who prowls or sneaks about; usually with unlawful intentions
[v] to go stealthily or furtively; "..stead of sneaking around spying on the neighbor's house"
[v] pass on stealthily; "He slipped me the key when nobody was looking"
[v] make off with belongings of others
[v] put, bring, or take in a secretive or furtive manner; "sneak a look"; "sneak a cigarette"
Synonyms
abstract, cabbage, canary, creep, filch, fink, hook, lift, mouse, nobble, pilfer, pinch, prowler, purloin, pussyfoot, slip, snarf, sneaker, snitch, snitcher, stalker, steal, stoolie, stoolpigeon, swipe