Working as Roman galley slave? (7)
I believe the answer is:
oarsman
'galley slave?' is the definition.
(thesaurus)
'working as roman' is the wordplay.
'working' is an anagram indicator.
'as'+'roman'='asroman'
'asroman' anagrammed gives 'OARSMAN'.
(Other definitions for oarsman that I've seen before include "One pulling in boat" , "One in a row" , "A ransom (anag)" , "Member of rowing crew" , "Male rower" .)