from
The Collaborative International Dictionary of English v.0.48
Perpendicular \Per`pen*dic"u*lar\, a. [L. perpendicularis,
perpendicularius: cf. F. perpendiculaire. See {Perpendicle},
{Pension}.]
1. Exactly upright or vertical; pointing to the zenith; at
right angles to the plane of the horizon; extending in a
right line from any point toward the center of the earth.
[1913 Webster]
2. (Geom.) At right angles to a given line or surface; as,
the line ad is perpendicular to the line bc.
[1913 Webster]
{Perpendicular style} (Arch.), a name given to the latest
variety of English Gothic architecture, which prevailed
from the close of the 14th century to the early part of
the 16th; -- probably so called from the vertical style of
its window mullions.
[1913 Webster]