Vertical1. (a.) Perpendicular to the plane of the horizon; upright; plumb; as, a vertical line.
2. (a.) of or pertaining to the vertex; situated at the vertex, or highest point; directly overhead, or in the zenith; perpendicularly above one.
3. (n.) Vertical position; zenith.
4. (n.) A vertical line, plane, or circle.
Thesaurus Entries
abrupt, acmatic, apical, arrowlike, azimuth circle, bluff, bold, bolt upright, breakneck, capital, chief, consummate, dead straight, direct, downright, erect, even, flat, head, headlong, headmost, highest, horizontal, in a line, level, lineal, linear, maximal, maximum, meridian, meridional, normal, orthodiagonal, overmost, paramount, perpendicular, plumb, plunging, precipitous, preeminent, rampant, rapid, rearing, rectilineal, rectilinear, right, right angle, ruler-straight, sharp, sheer, smooth, stand-up, standing up, steep, straight, straight-cut, straight-front, straight-side, straight-up, streamlined, summital, supreme, tip-top, top, topmost, TRUE, ultimate, unbending, unbent, unbowed, unbroken, uncurved, undeflected, undeviating, undistorted, uninterrupted, unswerving, unturned, up-and-down, upended, upmost, uppermost, upraised, upreared, upright, upstanding, vertical circle, zenithal