perpendicular
Cross references: 1. vertical 1. per.pen.dic.u.lar \.p*r-p*n-'dik-y*-l*r, .p*rp-*m-\ \.p*r-p*n-.dik-y*-'lar-*t-e-, .p*rp-*m-\ \-'dik-y*-l*r-le-\ aj [ME perpendiculer, fr. MF, fr. L perpendicularis, fr. perpendicu]lum plumb line, fr. per- + pende-re to hang - more at PENDANT 1a: exactly vertical or upright 1b: being at right angles to a given line or plane 2: extremely steep : PRECIPITOUS 3: of or relating to a medieval English Gothic style of architecture in wh ich vertical lines predominate 4: relating to, uniting, or consisting of individuals of dissimilar type o r on different levels - per.pen.dic.u.lar.i.ty n 2. perpendicular n 1: a line at right angles to the plane of the horizon or to another line or surface 2: in extremely steep face (as of a cliff)
Webster's English Dictionary