Definitions by ESBN

Thum 

A sex move when the woman sticks her thumb into the meatus (the lip of your dick) and rubs it until you cum.

Josh got to thum Victor the other day.

Thum by ESBN January 6, 2020

Thum 

A sex move when the woman sticks her thumb into a man's meatus (the lip of your penis) and rubs it until you cum.

Josh got to thum Victor the other day.

Thum by ESBN January 6, 2020