Personification of winter weather (4,5)
I believe the answer is:
jack frost
'personification of winter weather' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for jack frost that I've seen before include "Personification of a wintry morning" , "Freezing weather personified" , "Cold weather, personified" , "Winter personified" , "Personification of freezing weather" .)