caduceus vs insignia

caduceus and insignia both are nouns.

Word	Noun	Adjective	Verb	Adverb
caduceus	Yes	No	No	No
insignia	Yes	No	No	No

As nouns, insignia is a hypernym of caduceus; that is, insignia is a word with a broader meaning than caduceus:

caduceus: an insignia used by the medical profession; modeled after the staff of Hermes
insignia: a badge worn to show official position

caduceus (noun)	insignia (noun)
an insignia used by the medical profession; modeled after the staff of Hermes	a badge worn to show official position