sneak

(noun) a person who is regarded as underhanded and furtive and contemptible.

(noun) someone who prowls or sneaks about; usually with unlawful intentions. Synonyms: prowler, stalker.

(noun) someone acting as an informer or decoy for the police. Synonyms: fink, snitch, snitcher, stoolpigeon, stool pigeon, stoolie, sneaker, canary.

(verb) to go stealthily or furtively. Synonyms: mouse, creep, pussyfoot. Examples: "..stead of sneaking around spying on the neighbor's house."

(verb) put, bring, or take in a secretive or furtive manner. Examples: "Sneak a look." "Sneak a cigarette."

(verb) make off with belongings of others. Synonyms: pilfer, cabbage, purloin, pinch, abstract, snarf, swipe, hook, filch, nobble, lift.

(verb) pass on stealthily. Synonyms: slip. Examples: "He slipped me the key when nobody was looking."

(adj) marked by quiet and caution and secrecy; taking pains to avoid being observed. Synonyms: furtive, sneak(prenominal), sneaky, stealthy, surreptitious. Examples: "A furtive manner." "A sneak attack." "Stealthy footsteps." "A surreptitious glance at his watch."