Pitcher's pitch (6)
I believe the answer is:
slider
'pitcher's pitch' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for slider that I've seen before include "Control knob move up and down or sideways" , "Control such as on a mixing desk" , "American snack" , "Eg, fader control" , "Sir led (anag) - control mechanism" .)