In winter I'm expecting frost (4)
I believe the answer is:
rime
'frost' is the definition.
(rime is frost formed by freezing water vapour)
'in winter i'm expecting' is the wordplay.
'in' says the answer is hidden in the clue.
'RIME' is hidden in the letters of 'winter im expecting'.
(Other definitions for rime that I've seen before include "''The ... of the Ancient Mariner'' (Coleridge)" , "Ancient Mariner produced?" , "Frost left after freezing fog, or frozen dew" , "Hoar frost" , "Kind of frost in mire" .)