Perpendicular

Webster's Practical Dictionary- A Practical Dictionary of the Englih Language · 1884 · p. 305

per-pen-dik'u-ler, a. Exactly up cir right; at right angles to the plane of the horizon. {Geom.) At right angles to a given line or surface. — n. A line at right angles to the or plane of the horizon: a vertical cirline or direction. {Geom.) Aline or plane falling at right angles in on another line or surf sice. — Per- ■ pendic'ularlty, -l 'Y-tY, n. col- State of being perpendicular.