Definition of kicker
noun
1a person or animal that kicks. the player in a team who scores by kicking or who kicks to gain positional advantage.
2 informal an unexpected and often unpleasant discovery or turn of events:the kicker was you couldn’t get a permit an extra clause in a contract:Hale added a kicker to the mortgage
3 informal a small outboard motor.
4(in poker) a high third card retained in the hand with a pair at the draw.