Slimy act represented as 'spiritual' (8)
I believe the answer is:
mystical
'spiritual' is the definition.
(thesaurus)
'slimy act represented' is the wordplay.
'represented' indicates an anagram.
'slimy'+'act'='slimyact'
'slimyact' is an anagram of 'MYSTICAL'.
'as' is the link.
(Other definitions for mystical that I've seen before include "Inexplicable" , "Sacredly obscure" , "'Esoteric, spiritual (8)'" , "Inspiring spiritual awe" , "of occult rites" .)