Voluntary work supported by revolutionary Latino (8)
I believe the answer is:
optional
'voluntary' is the definition.
(I've seen this before)
'work supported by revolutionary latino' is the wordplay.
'work' becomes 'op' (abbreviation for opus).
'supported by' says to put letters next to each other (letters go below - in down clue).
'revolutionary' indicates an anagram.
'latino' with letters rearranged gives 'tional'.
'op'+'tional'='OPTIONAL'
(Other definitions for optional that I've seen before include "Such as one can take or leave" , "something extra?" , "'Elective, not obligatory (8)'" , "Platoon I may leave to choice" , "'Left to choice, not compulsory (8)'" .)