Green’s Dictionary of Slang

slough n.1

1. [1910s] (Aus.) a prison; a state of imprisonment [slough v. (1)].

2. (US) a convict.

3. [1920s–50s] (US Und., also cold slough) a temporarily empty house, thus a target for a robbery; thus cold slough prowler/worker, a thief who robs empty houses; cold slough job/prowli(ng), such a robbery.

In compounds

slough worker (n.) (also slough grafter)

[1900s–40s] (US Und.) one who robs a house or apartment in the absence of its owners; thus slough work, such a robbery.

In phrases

hot slough (n.) [hot adj. (5e)]

[1920s–60s] (US tramp) somewhere that is robbed while the owners are in occupation; thus hot slough worker, a thief who robs houses while the tenants are at home.