Seafront is for crew forced to abandon leader (9)
I believe the answer is:
promenade
'seafront' is the definition.
(I've seen this before)
'for crew forced to abandon leader' is the wordplay.
'for' becomes 'pro' (I've seen this before).
'crew' becomes 'men' (I've seen this before).
'forced' becomes 'made' (I've seen this before).
'to abandon leader' means to remove the first letter (I've seen 'abandoning leader' mean this).
'made' with its initial letter taken off is 'ade'.
'pro'+'men'+'ade'='PROMENADE'
'is' acts as a link.
(Other definitions for promenade that I've seen before include "Seafront walkway" , "Seafront walk" , "Place for strolling by the sea" , "Seaside walkway" , "Esplanade" .)