Sneer at this, potentially biting coated doughnut? (5)
I believe the answer is:
tarot
'sneer at this potentially' is the definition.
The definition suggests a singular noun which matches the answer.
'biting coated doughnut?' is the wordplay.
I cannot really see how this works, but
'doughnut?' could be 'o' (letter resembling a doughnut) and 'o' is found in the answer.
'biting' could be 'tart' (both can mean acerbic) and 'tart' is found within the leftover letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for tarot that I've seen before include "78-card pack" , "Cards used for fortune telling" , "Arcana cards" , "Fortune teller's seventy eight card pack" , "One in special suit" .)