- ICEUP
- Become difficult to drive on, in Minnesota
- Put on a slick coat
- Become frozen
- Freeze over
- Freeze
- Get a frosty coating
- Get a winter coat?
- Turn frosty
- Get frosty
- Freeze over, as the St. Lawrence
- Become translucent, as a windshield
- Freeze, in a way
- Get frosted
- Freeze solid
- Frost over
- Freeze, like a road
- Become unnavigable in winter
- Freeze, as a windshield
- Acquire a winter coat, in a way
- Get a dangerous winter coating
- Get a slick winter coat
- Acquire a winter coat?
- Glaze over, in a way
- Become unnavigable, as a sea in winter
- Acquire a wintry glaze
- Get slick, in a way
- Freeze, as a road
- Freeze, as a plane's wings
- Become unusable, as airplane wings
- Get slippery
- Make navigation difficult
- Become frosty
- Need defrosting
- Require defrosting
- Freeze over, as a windshield
- Become slippery, perhaps
- Become frozen, as a windshield
- Frost inconveniently
- Get wet, then freeze
- Get slick
- Become frosted.
- Frost, as a windshield
- Glaciate
- Become slippery, in a way
- Become blocked, in a way
- Get slippery, in a way
- Put on a winter coat?
- Coat in the winter
- Freeze over, as airplane wings
- Become slick, in a way
- Become impassable, in a way
- Glaze over
- Freeze over, as machinery
- Become unnavigable, perhaps
- Become unnavigable
- Become slippery, in winter
- Get slippery, in winter
- Become slippery in winter, in a way
- Glaciate, e.g.
- Acquire a wintry covering
- What windshields may do in January
- Get frosted, as glass
- Get more than frosty
- Become frosted, as glass
- Freeze, as glass
- Freeze on glass
- Freeze, as a window pane
- Become frost-covered
- Winter roads do it
- Become dangerous for driving
- Become dangerous, as roads
- Become frosted, as a windshield
- Become dangerously slippery, in a way
- Glaze over in winter
- Require scraping or salting, perhaps
- Get slick in winter
- Require salting, maybe
- Require scraping, as a windshield
- Require salt, perhaps
- Become more opaque, as windows
- Cover with a sheet?
- Freeze over, and a hint to a feature of 5-, 6-, 10-, 25- and 33-Down
