Spiritual guess (6)
I believe the answer is:
divine
This clue is a double definition.
'spiritual' is the first definition.
(thesaurus)
'guess' is the second definition.
(divining is a kind of guessing)
(Other definitions for divine that I've seen before include "Very good" , "Godlike or extremely beautiful" , "wonderful" , "Theologian" , "of a splendid nature" .)