trigonometric function vs circular function

trigonometric function and circular function both are nouns.

Word	Noun	Adjective	Verb	Adverb
trigonometric function	Yes	No	No	No
circular function	Yes	No	No	No

As nouns, trigonometric function and circular function are synonyms defined as:

trigonometric function and circular function: function of an angle expressed as a ratio of the length of the sides of right-angled triangle containing the angle

trigonometric function (noun)	circular function (noun)
function of an angle expressed as a ratio of the length of the sides of right-angled triangle containing the angle	function of an angle expressed as a ratio of the length of the sides of right-angled triangle containing the angle