What does underhand mean?

Answer 1

"Underhand" refers to a type of serve, and is the opposite of "overhand". An underhand serve is when the server holds the ball in front of them, at the height of their hip, and hits the ball out of their hand using their opposite fist or palm in order to serve. Meanwhile, an overhand serve is when the server tosses the ball in the air, over their head, in front of them, and uses their other hand to hit the ball in the air and over the net for a serve.