Search for Cockney over — abandoned? (8)
I believe the answer is:
untended
'abandoned?' is the definition.
(thesaurus)
'search for cockney over' is the wordplay.
'search for cockney' becomes ''unt' ('hunt' - I've seen this before - said with a cockney accent, dropping the 'H').
'over' becomes 'ended' (over can mean finished or ended).
'unt'+'ended'='UNTENDED'
(Other definitions for untended that I've seen before include "Left without attention or minder" , "Not looked after" , "Neglected" , "Not properly cared for" .)