Noun. singular. Has several definitions:
1) a white female who is unusually obsessed with 90's hip-hop acts, particularly The Beastie Boys.
2) a female who closely resembles a man, or has obvious masculine features (facial hair, etc.)
3) the female who plays the male role in a lesbian
4) a female who is usually pleasant, but does a complete 180 when on the rag
5) a very unconvincing drag queen
6) Chynna, the wrestler or Xena, the Warrior Princess.
Man 1:"Check out that tall, thick thang
Man 2: 'Dude, she looks like my brother...'
Man 3: "Yeah, that's a beastie bitch
Man 1: "Dog, why your wife actin a beast?"
Man 2: "You know what time it is.."