Spice enthusiast - Margaret (6)
I believe the answer is:
nutmeg
'spice' is the definition.
(I know that Nutmeg is a spice)
'enthusiast margaret' is the wordplay.
'enthusiast' becomes 'nut' (nut can mean an enthusiast or fan).
'margaret' becomes 'Meg' (short for Margaret).
'nut'+'meg'='NUTMEG'
(Other definitions for nutmeg that I've seen before include "Aromatic seasoning" , "Kernel and girl for a spice" , "Hard, aromatic spice" , "Hard seed of tropical tree ground as spice" , "Asian tree whose aromatic seed is used as spice when grated or ground" .)