Origanum vulgare vs oregano

Origanum vulgare and oregano both are nouns.

Word	Noun	Adjective	Verb	Adverb
Origanum vulgare	Yes	No	No	No
oregano	Yes	No	No	No

As nouns, Origanum vulgare and oregano are synonyms defined as:

Other synonyms of Origanum vulgare include marjoram, pot marjoram, wild marjoram, winter sweet.

Origanum vulgare (noun)	oregano (noun)
aromatic Eurasian perennial	pungent leaves used as seasoning with meats and fowl and in stews and soups and omelets
	aromatic Eurasian perennial