Ultimate issue: gold brought back in clutches of the Spanish (8)
I believe the answer is:
eventual
'ultimate' is the definition.
(similar in meaning)
'issue gold brought back in clutches of the spanish' is the wordplay.
'issue' becomes 'vent' (both can mean to give out).
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'brought back' says the letters should be written backwards.
'in clutches of' is an insertion indicator.
'the spanish' becomes 'el' ('the' in Spanish).
'au' backwards is 'ua'.
'vent'+'ua'='ventua'
'ventua' placed inside 'el' is 'EVENTUAL'.
(Other definitions for eventual that I've seen before include "Ensuing" , "Money such as bail" , "Final - happening as a consequence" , "Net value (anag.)" , "Coming at last, ultimate" .)