In the 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 the winter i'm expecting' is the wordplay.
'in' indicates a hidden word.
'RIME' is hidden within 'winter im expecting'.
(Other definitions for rime that I've seen before include "dated poetry" , "Ice" , "Hoarfrost" , "Kind of frost in mire" , "''The ... of the Ancient Mariner'' (Coleridge)" .)