A normal force diagram is a visual representation that displays the perpendicular force exerted on an object by a surface. However, there are several synonyms for normal force diagram that can be used interchangeably depending on the context. Some of the synonyms for normal force diagram include reaction force diagram, support force diagram, and vertical force diagram. These terms can be used in the field of physics and engineering to describe the relationship between the object and the surface it is in contact with. The normal force diagram is an essential tool for understanding the mechanics of an object and how it interacts with the environment.