tooth fungus vs fungus

tooth fungus and fungus both are nouns.

Word	Noun	Adjective	Verb	Adverb
tooth fungus	Yes	No	No	No
fungus	Yes	No	No	No

As nouns, fungus is a hypernym of tooth fungus; that is, fungus is a word with a broader meaning than tooth fungus:

tooth fungus: a fungus of the family Hydnaceae
fungus: an organism of the kingdom Fungi lacking chlorophyll and feeding on organic matter; ranging from unicellular or multicellular organisms to spore-bearing syncytia

tooth fungus (noun)	fungus (noun)
a fungus of the family Hydnaceae	an organism of the kingdom Fungi lacking chlorophyll and feeding on organic matter; ranging from unicellular or multicellular organisms to spore-bearing syncytia