Another British slang word with several meanings. As a noun it was originally used synonymously with "pimp" as spiregrain mentioned above, although I think that's become fairly obsolete these days.

For many people it retains its usage as a mildly offensive term for a gay man, but like a number of other British euphamisms for homosexuality it's started to fall out of favour as harsher, stronger-sounding American slang terms have come into use. Nowadays the word "ponce" is often used to describe someone who is acting pretentiously or as a bit of a poser: in an adjective form it has the same implication but can be applied to inanimate objects as well:

Example: "I don't like this wine bar, it's a bit too poncey for me"

As a verb ponce is slang for to borrow, or even to take, with undertones implying that the speaker knows that the request is a bit cheeky but relying on their friendship with the donor:

More examples:
"Can I ponce a lift back from the pub with you, mate?" -- if you were asking a friend for a ride home
"I'm gasping for a fag, can I ponce one off you?" -- have you got a cigarette because I really feel like I need one