When you're having anal sex with a girl and you're just finishing up, you punch them in the back of the head, making her ass hole contract so that when you pull out there's no shit on your dick.

Manuever performed during the sexual act either anal, or Doggy style. It's when the male punches the female in the back of the head, or neck prior to orgasm. Therefore causing the females vaginal and anal muscles to constrict helping make a more intense orgasmic experience.

The donkey punch when done correctly can provide pleasure, provide comedy, and wreak havoc at the same time. First, you must be making love in the less traditional way of the booty. Next, right before the money shot comes (no pun intended), rare back and use all of your strength to punch your lover in the back of the head. This causes a tightening of the anal canal, thus making your experience all the more pleasurable. When your lover wakes up, she wont remember a thing, but you will!

The act of playing Halo Reach online on a team slayer, aquiring a magnum or any other pistol, and meleing an enemy player from behind, resulting in an assassination animation.

if done correctly you should see the player's left hand punch the enemy in the back of the head, then a badass knife kill.

To strike a female forcefuly I the rear of her crainium at the point of climax during anal sex.
Often results in a bagel.

The lesser known and even lesser appreciated version of the Donkey Punch, wherein you perform the normal acts of a donkey punch but then proceed to grab onto a ceiling fan and swing around over her unconscious body, trying to shit in her mouth.

A punch to the back of the head or neck. The punch is delivered during anal sex. The purpose of the donkey punch is to cause the recipient's anus to clench tightly on the puncher's penis, thereby enhancing the puncher's sexual gratification. See donkey blow