1. in Und. use.
(a) [late 17C–1900s] an act of theft.
(b) [mid-18C+] (also sneaky) a thief.
(c) [mid-19C–1950s] a sneak-thief, i.e. a housebreaker who enters premises by taking advantage of unlocked doors, windows, etc.
(d) [late 19C–1950s] (US Und.) a bank robber (using guile rather than force).
2. [mid–late 19C] an unpleasant person, irrespective of tale-telling.
3. [mid-19C–1930s] (also sneaker) an escape.
4. [mid-19C+] (mainly teen) one who tells tales on their fellows, usu. in the context of school.
5. [late 19C] (US prison) a night-guard.
6. [1960s] (US black/gang) a sneak attack on a rival gang within their territory.
[1920s–30s] (US Und.) house-breaking.
[20C+] a surreptitious entrance and exit from a brothel.
1. [1900s] (Aus.) to inform against, to tell tales on.
2. [late 19C–1930s] (also make a sneak, make one’s sneak, take a sneak) to leave, to escape.
3. [1900s] (US) to approach surreptitiously.
[late 17C–late 19C] (UK Und.) to go out working as a sneak-thief or petty pilferer.
[late 17C+] surreptitiously, on the sly.
[1980s+] (US black) surreptitiously, deceitfully.
[1960s] (US black/gang) to enter a rival gang’s territory, usu. to harass or fight.