mercurial ointment vs unguent

mercurial ointment and unguent both are nouns.

Word	Noun	Adjective	Verb	Adverb
mercurial ointment	Yes	No	No	No
unguent	Yes	No	No	No

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

mercurial ointment: an ointment containing mercury
unguent: semisolid preparation (usually containing a medicine) applied externally as a remedy or for soothing an irritation

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

mercurial ointment (noun)	unguent (noun)
an ointment containing mercury	semisolid preparation (usually containing a medicine) applied externally as a remedy or for soothing an irritation