genus Artemisia vs old woman

genus Artemisia and old woman both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Artemisia	Yes	No	No	No
old woman	Yes	No	No	No

genus Artemisia (noun)	old woman (noun)
usually aromatic shrubs or herbs of north temperate regions and South Africa and western South America: wormwood, sagebrush, mugwort, tarragon	a woman who is old
	herb with greyish leaves found along the east coast of North America; used as an ornamental plant