randy

Hello, It is slang meaning hot,cool or being horny and you shouldn't use it in formal speech,only among close friends or better don't use it at all , it is rather street language as multani says;)

okayokay geil doesnt mean that sth is "cool" moreover it means "wow, damn its awesome" for instance if u talk about the new BMW 7 series / its way stronger than "cool" or if u see a girl in the club u say "geil" which means "wow, damn shes hot" btw its neither slang nor street language (whats street language?), its just colloqial german and ok its true that especially young people say it and u of course u can use it when ur talking with ur friends or people who are in ur age...