*turn (something) up*
Definition: to shorten a dress, skirt or pair of trousers by folding up the bottom edge. Sometimes this part is then sewn.
(This phrasal verb has more than one meaning)
E.g.1: I like these trousers, but they’re a bit long. Could you turn them up for me?
E.g.2: Oh no! I’ve just turned this skirt up, but I folded it the wrong way so now the wrong side of the material is showing.
This phrasal verb can be separated. (E.g.1 & 2)