As nouns the difference between backspin and underspin
is that backspin is spin applied to a ball in order to slow it, change its flight, or stop it when it lands while underspin is backspin.
As a verb backspin
is to spin (a ball) with this motion.
backspin
English
Noun
(-)
Spin applied to a ball in order to slow it, change its flight, or stop it when it lands.
Verb
To spin (a ball) with this motion.
See also
* check spin
* sidespin
* topspin