DictionarynormalPerpendicular direction
adjective / noun

normal

At right angles to a line or surface, or a line in that direction.

The diagram shows a line normal to the curved surface.

Etymology

The Latin adjective refers to the carpenter's square. Its geometric sense preserves that tool's right angle, describing a perpendicular line or direction.

More examples

  • Draw the normal at the point where the ray strikes.
  • The force acts in the normal direction.
  • Several normals were marked along the curve.

Forms

normal · normals

Similar words

perpendicular
The more familiar geometry term for a right-angle relationship.
orthogonal
A technical term, especially in mathematics.