What is the character or symbol representing an idea a thing expressing pronunciation of particular word words for it as in traffic sign commonly used no parking?

The character or symbol representing an idea, thing, or pronunciation of a word, used commonly on traffic signs for "no parking," is a diagonal slash through a circle.

This symbol is often referred to as a "no" symbol or a "prohibition symbol." It is used internationally to indicate that something is forbidden or not allowed.

In the context of traffic signs, the slash through the circle means that parking is not permitted in that area.