salivary calculus vs calculus

salivary calculus and calculus both are nouns.

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

As nouns, calculus is a hypernym of salivary calculus; that is, calculus is a word with a broader meaning than salivary calculus:

salivary calculus: a stone formed in the salivary gland
calculus: a hard lump produced by the concretion of mineral salts; found in hollow organs or ducts of the body

Other hypernyms of salivary calculus include concretion.

salivary calculus (noun)	calculus (noun)
a stone formed in the salivary gland	the branch of mathematics that is concerned with limits and with the differentiation and integration of functions
	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