Tangent adj. Touching; touching at a single point; specifically (Geom.) Meeting a curve or surface at a point and having at that point the same direction as the curve or surface; said of a straight line, curve, or surface; as, a line tangent to a curve; a curve tangent to a surface; tangent surfaces. Tangent plane (Geom.), a plane which touches a surface in a point or line.
Tangent scale (Gun.), a kind of breech sight for a cannon.
Tangent screw (Mach.), an endless screw; a worm.
