Lover of climbing heading for ledge further down (8)
I believe the answer is:
follower
'lover' is the definition.
(thesaurus)
'of climbing heading for ledge further down' is the wordplay.
'climbing' is a reversal indicator (in a down clue, letters climb up).
'heading for' suggests taking the first letters.
'further down' becomes 'lower' (I've seen this before).
The first letter of 'ledge' is 'l'.
'of' backwards is 'fo'.
'fo'+'l'+'lower'='FOLLOWER'
(Other definitions for follower that I've seen before include "One accepts the leadership of another" , "Disciple" , "Attendant" , "fan" , "Supporter" .)