circular function vs function

circular function and function both are nouns.

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

As nouns, function is a hypernym of circular function; that is, function is a word with a broader meaning than circular function:

circular function: function of an angle expressed as a ratio of the length of the sides of right-angled triangle containing the angle
function: (mathematics) a mathematical relation such that each element of a given set (the domain of the function) is associated with an element of another set (the range of the function)

Other hypernyms of circular function include map, mapping, mathematical function, single-valued function.

circular function (noun)	function (noun)
function of an angle expressed as a ratio of the length of the sides of right-angled triangle containing the angle	the actions and activities assigned to or required or expected of a person or group
	what something is used for
	a set sequence of steps, part of larger computer program
	a formal or official social gathering or ceremony of people
	a formal or official social gathering or ceremony
	(mathematics) a mathematical relation such that each element of a given set (the domain of the function) is associated with an element of another set (the range of the function)
	a relation such that one thing is dependent on another

circular function (verb)	function (verb)
	perform duties attached to a particular office or place or function
	perform as expected when applied
	serve a purpose, role, or function