Esoteric, spiritual (8)
I believe the answer is:
mystical
I believe this is a double definition.
'esoteric' is the first definition.
(similar in meaning)
'spiritual' is the second definition.
(thesaurus)
(Other definitions for mystical that I've seen before include "'Esoteric, spiritual (8)'" , "Slimy act? (anag)" , "of occult rites" , "Inexplicable" , "Inspiring spiritual awe" .)