Perpendicular

[pur-puh n-dik-yuh-ler] /ˌpɜr pənˈdɪk yə lər/

adjective
1.
vertical; straight up and down; upright.
2.
Geometry. meeting a given line or surface at right angles.
3.
maintaining a standing or upright position; standing up.
4.
having a sharp pitch or slope; steep.
5.
(initial capital letter) noting or pertaining to the last style of English Gothic architecture, prevailing from the late 14th through the early 16th century and characterized by the use of predominantly vertical tracery, an overall linear, shallow effect, and fine intricate stonework.
noun
6.
a perpendicular line or plane.
7.
an instrument for indicating the vertical line from any point.
8.
an upright position.
9.
a sharply pitched or precipitously steep mountain face.
10.
moral virtue or uprightness; rectitude.
11.
Nautical. either of two lines perpendicular to the keel line, base line, or designed water line of a vessel.
/ˌpɜːpənˈdɪkjʊlə/
adjective
1.
Also normal. at right angles to a horizontal plane
2.
denoting, relating to, or having the style of Gothic architecture used in England during the 14th and 15th centuries, characterized by tracery having vertical lines, a four-centred arch, and fan vaulting
3.
upright; vertical
noun
4.
(geometry) a line or plane perpendicular to another
5.
any instrument used for indicating the vertical line through a given point
6.
(mountaineering) a nearly vertical face
adj.

late 15c., from adverb (late 14c.), from Old French perpendiculer, from Latin perpendicularis “vertical, as a plumb line,” from perpendiculum “plumb line,” from perpendere “balance carefully,” from per- “thoroughly” (see per) + pendere “to weigh, to hang” (see pendant). As a noun from 1570s. Related: Perpendicularly; perpendicularity.
perpendicular
(pûr’pən-dĭk’yə-lər)
Adjective Intersecting at or forming a right angle or right angles.

Noun A line or plane that is perpendicular to a given line or plane.