arnica vs unguent

arnica and unguent both are nouns.

Word	Noun	Adjective	Verb	Adverb
arnica	Yes	No	No	No
unguent	Yes	No	No	No

As nouns, unguent is a hypernym of arnica; that is, unguent is a word with a broader meaning than arnica:

arnica: an ointment used in treating bruises
unguent: semisolid preparation (usually containing a medicine) applied externally as a remedy or for soothing an irritation

Other hypernyms of arnica include balm, ointment, salve, unction.

arnica (noun)	unguent (noun)
an ointment used in treating bruises	semisolid preparation (usually containing a medicine) applied externally as a remedy or for soothing an irritation
any of various rhizomatous usually perennial plants of the genus Arnica
used especially in treating bruises