Black ice is a thin invisible layer of ice on a road. Skid on black ice.
It is clear rather than black, and you see the road through it. Black ice forms first on bridges, because cold air gets underneath them as well.
1nounblack iceA thin invisible layer of ice on a road.
“The black ice put three cars in the same ditch.”
black ice is ice.
Practised in Weather & Seasons