a plane that is perpendicular to the vertical line or parallel with the horizon at a point

A transverse plane at right angle to the long axis of the body

A plane which lies in a crosswise direction.

A horizontal plane that divides the body into upper (superior) and lower (inferior) sections. Also called the transverse plane.

A plane that is parallel to the horizon; flat. A transverse plane.

An imaginary plane that is tangent (or parallel) to the earth's surface at a given location.

In astronomy, geography, geometry and related sciences and contexts, a plane is said to be horizontal at a given point if it is locally perpendicular to the gradient of the gravity field, i.e., with the direction of the gravitational force (per unit mass) at that point.