This word has several
slang meanings. They are:
1) To engage in casual sex with someone.
2) To give someone a dirty look (In
London at least).
3) To give someone a poor
deal.
Because of this, a sentence like "he screwed me" can be somewhat ambiguous and so context is important.
1) She's such a
slut, she screwed Billy the other night and Davey the night before.
2) So we broke up on Monday and then when he walked past me yesterday he screwed me and I just flipped out.
3) So I just wanted to buy those chocolate chip
cookies because they are the best thing on this Earth but oh my
god that guy in the shop screwed me over so much, I mean since when did five little cookies in a packet cost so much? I swear they were one pound yesterday and
now they're like four pounds, almost.