dative/locative singular of dupa

Used other than figuratively or idiomatically: see wrzód, dupa. / pain in the ass, a troublesome irritation

(colloquial, idiomatic, vulgar) hands down, like a knife through butter (with great ease and effectiveness)

(vulgar, idiomatic, slang, humorous) you don't know what you're talking about

(idiomatic, humorous, vulgar) completely dark, pitch black (devoid of any light)