noun: a Gothic style in 14th and 15th century England; characterized by vertical lines and a four-centered (Tudor) arch and fan vaulting
noun: a straight line at right angles to another line
noun: a cord from which a metal weight is suspended pointing directly to the earth's center of gravity; used to determine the vertical from a given point
adjective: intersecting at or forming right angles
Example: "The axes are perpendicular to each other"
adjective: extremely steep
Example: "The great perpendicular face of the cliff"
adjective: at right angles to the plane of the horizon or a base line