Spice: feature of Christmas morning, second to be consumed (8)
I believe the answer is:
cardamom
'spice' is the definition.
(I've seen this before)
'feature of christmas morning second to be consumed' is the wordplay.
'feature of christmas' becomes 'card' (as in a Christmas card).
'morning' becomes 'am'.
'second' becomes 'mo' (both are short periods of time).
'to be consumed' indicates putting letters inside.
'am' enclosing 'mo' is 'amom'.
'card'+'amom'='CARDAMOM'
(Other definitions for cardamom that I've seen before include "It's pungent" , "Seeds used as spice" , "something spicy" , "Spice; a mad corm (anag.)" , "Roc, Madam, may become a herb" .)