A situation where one or severall persons behave like donkeys.
In poker a donkey, or "donk" is a person with inferior understanding of the game and who basically play the "wrong" way.
Due to the fact that there is randomness in poker, sometimes the "wrong" move may result in winning a pot against a wiser player. When a really silly move ends up in winning the pot due to a very unlikely draw hitting, you can call this a donkament.
Quotes that I heard :
"I'll never play online during week ends again, it's such donkaments"
A very large poker tournament, mostly full of shitty players, aka donks. They are hard to win because these shitty ass players seem to always get lucky.
Rob: I just played a donkament on stars
Joe: didja win?
Joe: lol donkaments