Omnivorous US hillbillies eating this? (5)
I believe the answer is:
sushi
'this?' is the definition.
The definition suggests a singular noun which matches the answer.
'omnivorous us hillbillies eating' is the wordplay.
'eating' indicates a hidden word.
'SUSHI' is hidden within 'omnivorous us hillbillies'.
(Other definitions for sushi that I've seen before include "Japanese cold rice dish" , "Japanese food" , "Rice and raw fish wrapped in seaweed" , "Fated" , "'Dish of rice, vegetables and raw fish (5)'" .)