When you donkeythump someone, you fuck them in the ass and when you're about to blow your load you whack them on the back of the head so they clench. I have experience with this myself.
I donkeythump, therefore I am, although have been donkeythumped myself several times
ayon kay MarineJulio ika-05 ng Mayo, 2004
2 more definitions
When pounding a girl in the ass, right before you spurt you thump her upside the head, knocking her out causing all her muscles to contract giving the greatest pleasure in your life.
oh shit here it comes!! oh god! wait hold... on... im gonna donkey thump you!... (whack) oh..... jesus!
ayon kay Blake Sprunk ika-09 ng Hunyo, 2003
An involuntary meeting usually intiated by your supervisor that is generally considered a waste of time. When over it generally leaves one feeling fucked up the ass without the lube.
Five minutes after my shift began my supervisor came to me to talk. I knew that I was in for a donkey thump.
ayon kay Sling366 ika-05 ng Agosto, 2008