Worries about Greek god (5)
I believe the answer is:
cares
'worries' is the definition.
(I've seen this before)
'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" .)