Answer: icedup

AnswerCrossword Clue
ICEDUP

Got frozen

ICEDUP

Acquired a slick coat

ICEDUP

Got slick

ICEDUP
Needing defrosting
ICEDUP
Froze solid
ICEDUPBecame dangerous to drive in December
ICEDUPFroze over
ICEDUPGot dangerous, as a road, perhaps
ICEDUPFrost-covered
ICEDUPFrozen over
ICEDUPFroze
ICEDUPFrosted
ICEDUPJammed, in a way
ICEDUPNeeded a coating of heated propylene glycol, say
ICEDUPBecame a winter hazard, as a road
ICEDUPSlick, in a way
ICEDUPGot frosty
ICEDUPBecame slick
ICEDUPLike some winter windshields