I found a problem into the title of the recent song "California gurls", by Katy Perry. It is "gurls". What does it mean? This word isn't in the lyrics: during the song, Katy sings "...california girls...". So I suppose that gurl is a synonym for girl. But I wonder: is there a rule? Are there exceptions? Is it American slang? Can i use it with a Britishman? Could you help me to understand, please? Thanks P.S.: If I made any grammatical errors, please report it to me. Thank you! Edit: Are there any differences in pronunciation between the two terms?