1. The act of balling one's hand up into a tight fist, and placing it into your partner's vagina, either vigorously or delicately. However it is usually rythmic.
2. The sensual act of ever so delicately teasing a woman lovingly, then suddenly penetrating with your entire fist. Can be quite effective when combined with suspenseful music. Make sure to wait until the climax of the song to ram your entire fist in.
3. Commonly referred to as a "hit below the waist" in boxing matches.
"Yo Derek I totally put a chick in the hospital last night!"
"Dude you didn't use roofies again did you?"
"Heck no man, I was cooterfisting!"