Can a god go evil, ultimately? (7)
I believe the answer is:
aerosol
'can' is the definition.
(I've seen this before)
'a god go evil ultimately?' is the wordplay.
'god' becomes 'eros' (Eros is an example).
'ultimately?' says to take the final letters (I've seen 'ultimately' mean this).
The last letters of 'go evil' are 'ol'.
'a'+'eros'+'ol'='AEROSOL'
(Other definitions for aerosol that I've seen before include "Pressurised container releasing fine spray" , "fog?" , "Pressurized container" , "A suspension" , "Atomiser" .)