Bourbon flavoring (3)
I believe the answer is:
oak
'bourbon flavoring' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for oak that I've seen before include "Acorn-bearing tree" , "Acorns are its fruit" , "From little acorns does it grow" , "Its seed is the acorn" , "Deciduous forest tree" .)