I. |pər]pən|dikyələr, |pə̄]...lə(r, |pəi]...lə(r, ]p ə m|d- adjective
Etymology: alteration (influenced by Latin perpendicularis ) of Middle English perpendiculer, from Middle French, from Latin perpendicularis, from perpendiculum plumb line (from per- through + pendēre to hang + -iculum, suffix denoting an instrument) + -aris -ar — more at per- , pendant
1.
a. : standing at right angles to the plane of the horizon : pointing to the zenith : exactly vertical or upright
measure the perpendicular height
b. : being or set at right angles to a given line or plane
the lines are perpendicular to each other
an almost perpendicular rise in share prices — U.S. News & World Report
2. obsolete : leading directly to : immediate
perpendicular cause
3. : extremely steep : precipitous
a lofty perpendicular cliff — E.V.Lucas
4. of a person
a. : erect in bearing
a perpendicular retired colonel
b. : standing up
a bus … its platform weighed down with perpendicular men — Bruce Marshall
5. : of, relating to, or in a medieval English Gothic style of architecture in which vertical lines predominate
6. : relating to, uniting, or consisting of individuals of dissimilar type or on different levels
perpendicular , in the sense of providing a strand that will run through both high school and college, uniting different ages — General Education in a Free Society
Synonyms: see vertical
II. noun
( -s )
1.
a. : a line at right angles to another line or plane
b. : a line through a vertex at right angles to the opposite side or face in a triangle or tetrahedron
2. : an instrument for indicating the vertical line from any point
3.
a. : a line at right angles to the plane of the horizon : a vertical line or direction
b. : a vertical plane
c. : an extremely steep or precipitous face (as of a mountain)