Climber’s aid is fiddle around slope (7)
I believe the answer is:
crampon
'climber's aid' is the definition.
(I've seen this before)
'fiddle around slope' is the wordplay.
'fiddle' becomes 'con' (both can mean a scam).
'around' is an insertion indicator.
'slope' becomes 'ramp' (I've seen this before).
'con' enclosing 'ramp' is 'CRAMPON'.
'is' acts as a link.
(Other definitions for crampon that I've seen before include "Climber's aid" , "Grappling-iron" , "Climber's boot spikes" , "helps climber on ice" , "Spiked plate for a climbing boot" .)