Seasonal visitors (4)
I believe the answer is:
magi
'seasonal visitors' is the definition.
(the Magi or wise men who visited Jesus)
This is the entire clue.
(Other definitions for magi that I've seen before include "Three Wise Men of the Bible" , "Three Wise Men from the East" , "Priests" , "members of priestly caste" , "The sages who visited Jesus and Mary and Joseph shortly after Jesus was born" .)