trigonometric /-nə-metˈrik/ or trigonometˈrical adjective

trigonometˈrically adverb

trigonometrical point noun (geography, etc)

In triangulation, a fixed point whose position as vertex of a triangle is calculated astronomically (often shortened to trig point)

trigonometric function and trigonometric ratio noun

Any function of an angle that is defined by the relationship between the angles and sides of a right-angled triangle