Pit worker against a goddess (7)
I believe the answer is:
minerva
'goddess' is the definition.
(thesaurus)
'pit worker against a' is the wordplay.
'pit worker' becomes 'miner' (I've seen this before).
'against' becomes 'v' (abbreviation for 'versus').
'miner'+'v'+'a'='MINERVA'
(Other definitions for minerva that I've seen before include "embodiment of wisdom" , "Roman goddess of crafts and wisdom - a vermin (anag)" , "Roman goddess of learning" , "female of great wisdom" , "wise goddess" .)