noun Date: 1909 a function (as the sine, cosine, tangent, cotangent, secant, or cosecant) of an arc or angle most simply expressed in terms of the ratios of pairs of sides of a right-angled triangle, the inverse (as the arcsine, arccosine, or arctangent) of a ~
TRIGONOMETRIC FUNCTION
Meaning of TRIGONOMETRIC FUNCTION in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012