adj. & n.
adj. 1 at right angles to a horizontal plane, perpendicular. 2 in a direction from top to bottom of a picture etc. 3 of or at the vertex or highest point. 4 at, or passing through, the zenith. 5 Anat. of or relating to the crown of the head. 6 involving all the levels in an organizational hierarchy or stages in the production of a class of goods (vertical integration).
n. a vertical line or plane. out of the vertical not vertical. vertical angles Math. each pair of opposite angles made by two intersecting lines. vertical fin Zool. a dorsal, anal, or caudal fin. vertical plane a plane at right angles to the horizontal. vertical take-off the take-off of an aircraft directly upwards. verticality n. verticalize v.tr. (also -ise). vertically adv.
[ F vertical or LL verticalis (as VERTEX) ]