She has a reputation for being 'good/great in the sack'. [=for being a good sexual partner]
He's ready to 'jump/climb in the sack' [=have sex] with any woman who'll have him.
The company 'gave him the sack' [=fired him] for improper conduct.
(..) l was going to school 'til l met somebody. - Met somebody? - Yeah. Uh, two big monsters... with big green eyes! - Why, l-- l-- - Monsters? - Weren't you afraid? - No, ma'am. But they tied me in a big sack. You don't say! And where was SirJiminy? Eh, huh? Oh,Jiminy? Hey, psst! Leave me outta this. They put him in a little sack. - No! - Yeah! - How did you escape? - l didn't. They chopped me into fi rewood. Oh! Oh, look! My nose! What's happened? (..)1940 Pinocchio