adj touching; touching at a single point.
2. tangent ·adj 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.
3. tangent ·vt a tangent line curve, or surface; specifically, that portion of the straight line tangent to a curve that is between the point of tangency and a given line, the given line being, for example, the axis of abscissas, or a radius of a circle produced. ·see trigonometrical function, under function.