Angelica Archangelica vs archangel

Angelica Archangelica and archangel both are nouns.

Word	Noun	Adjective	Verb	Adverb
Angelica Archangelica	Yes	No	No	No
archangel	Yes	No	No	No

As nouns, Angelica Archangelica and archangel are synonyms defined as:

Angelica Archangelica and archangel: a biennial cultivated herb; its stems are candied and eaten and its roots are used medicinally

Other synonyms of Angelica Archangelica include garden angelica.

Angelica Archangelica (noun)	archangel (noun)
a biennial cultivated herb; its stems are candied and eaten and its roots are used medicinally	an angel ranked above the highest rank in the celestial hierarchy
	a biennial cultivated herb; its stems are candied and eaten and its roots are used medicinally