A new hint regarding what could whet the appetite (9)
I believe the answer is:
antipasto
'what could whet the appetite' is the definition.
I can't tell whether this definition defines the answer.
'a new hint regarding' is the wordplay.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'hint' becomes 'tip' (synonyms).
'regarding' becomes 'as to' (I've seen this in another clue).
'a'+'n'+'tip'+'asto'='ANTIPASTO'
Can you help me to learn more?
(Other definitions for antipasto that I've seen before include "Appetiser, starter" , "Italian food" , "Appetizers in an Italian meal" , "course of hors d'oeuvres" , "Italian dish" .)