Definitions

1. noun

A person who or thing that thwacks, especially a device used for administering a sharp blow or for beating or striking something.

“The coach was known as a thwacker for her tough but fair approach to training the team.”

2. verb

To strike or hit (something or someone) with a sharp, flat blow, typically with the flat of the hand or a flat object.

“She thwacked the ball with her racket, sending it flying across the court.”