The term donkbet comes from the combination of donkey and bet. Such a bet is an unexpected or risky bet by a player who was not the aggressor in the previous round, often into a player who was the aggressor. This is also called a gaybet or bet out of nowhere.
A typical situation for a donkbet is when a player calls a raise in the first round then bets into the raiser in the next round.
Donkbets can be dumb moves by inexperienced players, or deceptive maneouvers made to trick an opponent since they are often viewed as weak. Furthermore, they are used as blockbets in variants with variable bet sizes, where a small bet can be made to keep an opponent from making a large, pot odds-spoiling bet.