oregano vs origanum

oregano and origanum both are nouns.

Word	Noun	Adjective	Verb	Adverb
oregano	Yes	No	No	No
origanum	Yes	No	No	No

As nouns, origanum is a hypernym of oregano; that is, origanum is a word with a broader meaning than oregano:

oregano: aromatic Eurasian perennial
origanum: any of various fragrant aromatic herbs of the genus Origanum used as seasonings

oregano (noun)	origanum (noun)
pungent leaves used as seasoning with meats and fowl and in stews and soups and omelets	any of various fragrant aromatic herbs of the genus Origanum used as seasonings
aromatic Eurasian perennial