antinormal

Meanings

1. Antagonistic to or causing deviations from that which is considered normal.
2. In the opposite direction or position from what is normal or canonical.
3. Perpendicular to a tangent of a curve or tangent plane of a surface but pointing opposite to convention.

1. A normal that points opposite to convention. For example, in solid geometry it is conventional for normals to point outwards, so an antinormal in solid geometry refers to a normal pointing inwards.

Etymology

From anti- + normal.