smut fungus vs fungus

smut fungus and fungus both are nouns.

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

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

smut fungus: any fungus of the order Ustilaginales
fungus: an organism of the kingdom Fungi lacking chlorophyll and feeding on organic matter; ranging from unicellular or multicellular organisms to spore-bearing syncytia

smut fungus (noun)	fungus (noun)
any fungus of the order Ustilaginales	an organism of the kingdom Fungi lacking chlorophyll and feeding on organic matter; ranging from unicellular or multicellular organisms to spore-bearing syncytia