tophus vs calculus

tophus and calculus both are nouns.

Word	Noun	Adjective	Verb	Adverb
tophus	Yes	No	No	No
calculus	Yes	No	No	No

As nouns, tophus and calculus are synonyms defined as:

Other synonyms of tophus include tartar.

tophus (noun)	calculus (noun)
an incrustation that forms on the teeth and gums	the branch of mathematics that is concerned with limits and with the differentiation and integration of functions
a deposit of urates around a joint or in the external ear; diagnostic of advanced or chronic gout	a hard lump produced by the concretion of mineral salts; found in hollow organs or ducts of the body
	an incrustation that forms on the teeth and gums