Three Wise Men (4)
I believe the answer is:
magi
'three wise men' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for magi that I've seen before include "Nativity story wise men" , "Star witnesses" , "Caspar, Melchior and Balthasar" , "Christmas travellers" , "Wise men, visitors to Bethlehem" .)