Santa's aide (3)
I believe the answer is:
elf
'santa's aide' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for elf that I've seen before include "Mischievous fairies" , "One of the little folk" , "Supernatural creature of folk tales" , "Imaginary small being of selfish kind" , "Santa's helper" .)