Slice
Slice in padel describes the way the player cuts from high to low at the ball.
Backspin that results in the ball bouncing low and slow off the ground and the back wall. This is often applied to deep volleys aggressively.
Slice is also used in bandejas to keep the ball low after it bounces off the ground and/or back glass.
Roughness
The application of a rough surface on a padel racket's face in order to assist players in generating spin on their shots.