perpendicular

perpendicular is an Adverb

Definition:

[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.

[2] At right angles to a given line or surface; as, the line ad is perpendicular to the line bc. 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.