Worries about Greek god (5)
I believe the answer is:
cares
'worries' is the definition.
(I've seen this in another clue)
'about greek god' is the wordplay.
'about' becomes 'c' (abbreviation for circa).
'greek god' becomes 'ares' (Ares is an example).
'c'+'ares'='CARES'
(Other definitions for cares that I've seen before include "Worries, anxieties" , "Has concerns or interest" , "Minds" , "Feels interest or concern" .)