Point on which a lever turns (7)
I believe the answer is:
fulcrum
'point on which a lever turns' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for fulcrum that I've seen before include "Point against which a lever rests" , "Pivot about which a lever turns" , "place to get a purchase!" , "Pivot on which a lever moves" , "Lever's pivot" .)