An abbreviation that = (P)retty (H)ot (A)nd (T)hick Despite the previous definitions, this is the modern definition for the abbreviation! Used to describe a beautiful girl.
Cool Girl: Does this sundress make me look fat?
Cool Guy: Nah, if anything it makes you look Phat, Pretty Hot and Thick.
In the 80s, an 18 year old inner-city black kid from Richmond, Virginia told me that it stood for "Pussy, Hips, Ass, Tits", And he told me this around 1985. So that word is AT LEAST 27 years old. True Story. Just thought I'd share with you.
Phat does mean Pretty Hot And Tempting, like the other definitions say. The problem with "phat" is that it is no longer in really. It has kind of phased out and is mostly used by wannabes, lowerclassmen in high school, or middle schoolers. It is now considered a slang faux pas. I wouldn't use it if I was you.