Perpendicular

Exactly upright or vertical; pointing to the zenith; at right angles to the plane of the horizon; extending in a right line from any point toward the center of the earth.

At right angles to a given line or surface; as, the line ad is perpendicular to the line bc.

A line at right angles to the plane of the horizon; a vertical line or direction.

A line or plane falling at right angles on another line or surface, or making equal angles with it on each side.

at right angles to the plane of the horizon or a base line; "a vertical camera angle"; "the monument consists of two vertical pillars supporting a horizontal slab"; "measure the perpendicular height"

a Gothic style in 14th and 15th century England; characterized by vertical lines and a four-centered (Tudor) arch and fan vaulting