At party, expressing disgust, as enthusiast describes little cake (8)
I believe the answer is:
doughnut
'little cake' is the definition.
'doughnut' can be an answer for 'cake' (I have seen 'Small cake' mean 'doughnut' so perhaps 'cake' could also mean 'doughnut'). I am not certain of the 'little' bit.
'at party expressing disgust as enthusiast' is the wordplay.
'at' says to put letters next to each other.
'party' becomes 'do' (do can informally mean a party).
'expressing disgust as' becomes 'ugh' (I can't justify this - if you can you should believe this answer much more).
'enthusiast' becomes 'nut' (nut can mean an enthusiast or fan).
'do'+'ugh' is 'dough'.
'dough'+'nut'='DOUGHNUT'
'describes' is the link.
Can you help me to learn more?
(Other definitions for doughnut that I've seen before include "Small fried cake with hole in middle" , "Sweet fried snack" , "Sweet fried cake" , "Small tasty cake with hole in middle" , "Ring-shaped object" .)