To dine out with a girl is heavenly (6)
I believe the answer is:
divine
'heavenly' is the definition.
(similar in meaning)
'to dine out with a girl' is the wordplay.
'to dine out' becomes 'vine' (I am not sure about this - if you are sure you should believe this answer much more).
'with' is a charade indicator (letters next to each other).
'a girl' becomes 'Di' (short for Diane or Diana).
'vine' put after 'di' is 'DIVINE'.
'is' is the link.
Can you help me to learn more?
(Other definitions for divine that I've seen before include "Predict" , "Theologian" , "Sacred; excellent" , "Search for water with a rod" , "of a splendid nature" .)