licorice flavor source (7)
I believe the answer is:
aniseed
(Other definitions for aniseed that I've seen before include "Flavouring of e.g. absinthe" , "Liquorice flavouring -- ie Danes (anag)" , "Flavouring in pastis" , "Flavouring of sambuca" , "Liquorice flavouring, used in cookery" .)