NORMAL

(Lat. norma, a rule.) An adjective signifying that the ordinary structure peculiar to a family, a genus,or a species, is in no wise departed from. Normal. A term sometimes used for perpendicular. In the geometry of curve lines, the normal to a curve at any point is a straight line perpendxular to the tangent at that point, and included between the curve and the axis of the [s. 848]