tangent >> ˈtan(d)ʒ(ə)nt
Definition: [noun] a straight line or plane that touches a curve or curved surface at a point, but if extended does not cross it at that point.
Definition: [noun] a completely different line of thought or action.
Example: Loretta's mind went off at a tangent
Definition: [noun] the trigonometric function that is equal to the ratio of the sides (other than the hypotenuse) opposite and adjacent to an angle in a right-angled triangle.
Definition: [adjective] (of a line or plane) touching, but not intersecting, a curve or curved surface.
Example: this curve is tangent to the average cost curve