Definition:Cotangent/Linguistic Note

Linguistic Note on Cotangent
Like tangent, the word cotangent comes from the Latin tangentus that which is touching, the present participle of tangere to touch.

The co- prefix, as with similar trigonometric functions, is a reference to complementary angle: see Cotangent of Complement equals Tangent.

It is pronounced with an equal emphasis on both the first and second syllables: co-tan-jent.