…mount spaced out in range (3)
I believe the answer is:
nag
'mount' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for nag that I've seen before include "plague" , "Be persistently painful" , "Worry; old horse" , "Equine" , "Complain to or badger incessantly" .)