One of the gifts of the Magi (5)
I believe the answer is:
myrrh
'one of the gifts of the magi' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for myrrh that I've seen before include "fragrant substance" , "One gift of the Magi" , "Bitter tree gum, used in perfume and incense" , "Nativity gift" , "One of the first ever Christmas presents" .)