Wintry weather (4)
I believe the answer is:
snow
'wintry weather' is the definition.
(weather occurring in winter)
This is the entire clue.
(Other definitions for snow that I've seen before include "It falls in flakes" , "Jon - - (Ch.4 News)" , "Wintry flakes?" , "Precipitation falling as flakes" , "Settler" .)