Good time with a deity (4)
I believe the answer is:
faun
'deity' is the definition.
(faun is a kind of deity)
'good time with a' is the wordplay.
'good time' becomes 'fun' (I am not sure about this - if you are sure you should believe this answer much more).
'with' means one lot of letters goes inside another.
'fun' going around 'a' is 'FAUN'.
Can you help me to learn more?
(Other definitions for faun that I've seen before include "mythical deity" , "Deity in human shape, with horns and a goat's tail" , "Ancient Italian deity with goat-like features" , "Rural deity, half-man, half-goat" , "Roman deity, in the form of a man with a goat's horns, legs and tail" .)