Orca, able to destroy fish (8)
I believe the answer is:
'fish' is the definition.
(albacore is a kind of fish)
'orca able to destroy' is the wordplay.
'to destroy' is an anagram indicator (I've seen 'destroyed' mean this).
'orcaable' is an anagram of 'ALBACORE'.
(Other definitions for albacore that I've seen before include "Large tuna; able orca (anag.)" , "fish" , "Long-fin tunny" , "Variety of tuna" .)