Fancy a drink?
What it really means
"Fancy" means "want" or "feel like". "Fancy a drink?" is a casual invitation to go for a drink, often at the pub. You can fancy anything: "fancy a coffee?", "fancy a walk?". "Fancy someone" means to find them attractive.
Context, tips & common mistakes
'Fancy' here means 'do you want' — 'fancy a drink?', 'fancy a coffee?', 'fancy chips?' are all casual invitations, and 'fancy a drink?' specifically usually proposes the pub. Accepting is easy; declining well is the skill: 'I'll give it a miss tonight, but next time!' refuses the event while accepting the friendship, which is the entire point.
One homograph to manage: 'fancy' also means romantic attraction — 'I think he fancies you' — and the two coexist without much confusion, since 'fancy a drink?' from a colleague at 5pm is a social default, not a declaration. Invitations here are often deliberately low-key; treat the casualness as camouflage, because turning up matters more than the wording suggested.