slap
Definitions
To strike someone or something with the palm of the hand or a flat object.
To put or place something down quickly, forcefully, or carelessly.
An act of striking someone or something with the palm of the hand.
Examples
The sudden slap of the waves against the boat startled the passengers.
He gave his forehead a quick slap when he realized he had forgotten his keys.
It was a slap in the face to be excluded from the project after all his hard work.