tangent

A new subject that takes a conversation away from its main subject.

• Sorry, I went off on a tangent.
• Her question sent the discussion off on a tangent.
• The speaker's tangents made the lecture hard to follow.

How to use it: go off on a tangent (He went off on a tangent about his school days.)

Similar words: digression

Common phrases: on a tangent, off on a tangent

A straight line that touches a curved line at one point without passing across it there.

• Draw a tangent here.
• The tangent touches the circle at point A.
• We calculated the slopes of three tangents.

How to use it: tangent to something (Draw a tangent to the circle at this point.)

Common phrases: draw a tangent, tangent to something

An angle's sine divided by its cosine; in a right triangle, the opposite side divided by the adjacent side.

• Calculate the tangent of this angle.
• The tangent of forty-five degrees is one.
• We used a calculator to find the tangent.

How to use it: tangent of an angle (Find the tangent of this angle.)

Common phrases: tangent of something, calculate the tangent

Straight, without a curve to either side, especially when describing a road or railway.

• The train reached tangent track.
• This tangent section runs beside the river.
• Engineers inspected the tangent stretches of the railway.

Similar words: straight

Opposites: curved

Common phrases: tangent track, tangent section, tangent alignment