Whogina is a mixture between Whore and Vagina. Typically used as an insult but also common to use toward your close friends. Very offensive to girls, but the perfect word to describe a mega slutty bitch.
Guy 1: Dude, Lauren slept with 4 guys this weekend and all of them had girlfriends- who she's friends with.
Guy 2: God Lauren is such a whogina!!!
Girl Best friend 1: Hey slut!
Girl best friend 2: Hey Whogina!