Green’s Dictionary of Slang

prough n.

also pruck, prugh
[Scot. pruch, a perquisite; ult. prog v. (1)]

(Ulster) anything gained for free, a perquisite, esp. when illicitly come by.

[Ire]Share Slanguage 224/1: prough/prugh/pruck [n.pl. cf. Sc. pruch, perks] (Ulster) Material possessions, esp. illegally come by; free gifts.