Reach series of peaks (5)
I believe the answer is:
range
This clue is a double definition.
'reach' is the first definition.
(I know that reach can be written as range)
'series of peaks' is the second definition.
(mountain range)
(Other definitions for range that I've seen before include "Wander freely" , "Distance aircraft can travel" , "Vocal compass" , "Cooking appliance" , "Open grazing land or cooking stove" .)