n.[C]

1. 【數】正切；切線
   They changed their course to something like a tangent to the earth.

   他們將航線改變為差不多與地球呈正切的方向。

2. （鐵路或道路的）直線區間

a.

1. 【數】正切的；相切的；切線的
   tangent circles

   相切的圓

2. 離題的；背離原來途徑的
   tangent remarks

   離題的話

n.

1. 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.
2. Mathematics  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.
3. a completely different line of thought or action:
   my mind went off at a tangent.

adj.