at a tangent Definition

tangent
noun

1. geom.
A straight line that touches a curve at one point, and has the same gradient (sense 3) as the curve at the point of contact.
2. trig.
A function (noun 4) of an angle in a right-angled triangle, defined as the length of the side opposite the angle divided by the length of the side adjacent to it.

adj

1. Belonging or relating to a tangent.
2. Touching, without intersecting.

Idiom: at a tangent

In a completely different direction or course.

Etymology: 16c: from Latin tangens, tangentis touching.