Foot pedal (7)
I believe the answer is:
treadle
'foot pedal' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for treadle that I've seen before include "Foot lever powering machine" , "Machine foot-lever" , "Related (anag.)" , "operate a spinning-wheel" , "Foot-pedal" .)