Slope conquered by bluff, spiky climber's friend? (7)
I believe the answer is:
crampon
'spiky climber's friend?' is the definition.
(spiky plate used by rock climbers)
'slope conquered by bluff' is the wordplay.
'slope' becomes 'ramp' (I've seen this before).
'conquered by' means one lot of letters goes inside another (inserted letters are conquered or contained).
'bluff' becomes 'con' (bluff can mean a trick or con).
'ramp' placed within 'con' is 'CRAMPON'.
(Other definitions for crampon that I've seen before include "Gripping device" , "Spiked plate for a climbing boot" , "helps climber on ice" , "Climber's boot spikes" , "Climbing device" .)