Related Clues:

• Freeze
• Glaciate
• Get slick, in a way
• Get slippery, in winter
• Become slippery, in winter
• Become dangerous for driving
• Get frosty
• Freeze over
• Become slippery in winter, in a way
• Require defrosting
• Become slippery, in a way
• Glaciate, e.g.
• Cover with frost
• Become dangerous, as roads
• Frost over