Article, at that time, on a Greek goddess (6)
I believe the answer is:
athena
'greek goddess' is the definition.
(I've seen this before)
'article at that time on a' is the wordplay.
'article' becomes 'a' (the indefinite article in English).
'at that time' becomes 'then' (synonyms).
'on' says to put letters next to each other.
'a'+'then'+'a'='ATHENA'
(Other definitions for athena that I've seen before include "One-time goddess" , "Greek goddess of wisdom etc." , "wise but fierce goddess" , "Greek goddess of a capital city" .)