A _ curve is when only the entrance to the curve is visible - you have no idea what the rest of the curve looks like

Blind curve

Explanation:

A blind curve on the road refers to a curve where the driver can only see the entrance of the curve but the rest of the curve is hidden from view thereby making the driver blind to the whole curve.

These curves can be quite dangerous if not approached carefully as they can lead to accidents when for instance cars that didn't see each other collide. For this reason there are many warning signs when approaching such curves.