(geometry) at or forming a right angle (to something). / Exactly upright; extending in a straight line toward the centre of the earth, etc. / Independent of or irrelevant to each other; orthogonal.

(geometry) A line or plane that is perpendicular to another. / A device such as a plumb line that is used in making or marking a perpendicular line.

(architecture) Of a style of English Gothic architecture from the fourteenth and fifteenth centuries, marked by stiff and rectilinear lines, mostly vertical window-tracery, depressed or four-centre arch, fan-tracery vaulting, and panelled walls.

The condition of being perpendicular.

plural of perpendicular

Quality of being perpendicular.

plural of perpendicularity

A technique of creating magnetic data storage using vertical as opposed to longitudinal magnetization.

plural of perpendicular pronoun

(humorous, derogatory) The first-person singular pronoun "I".