nasal canthus vs canthus

nasal canthus and canthus both are nouns.

Word	Noun	Adjective	Verb	Adverb
nasal canthus	Yes	No	No	No
canthus	Yes	No	No	No

As nouns, canthus is a hypernym of nasal canthus; that is, canthus is a word with a broader meaning than nasal canthus:

nasal canthus: the inner corner of the eye
canthus: either of the corners of the eye where the upper and lower eyelids meet

nasal canthus (noun)	canthus (noun)
the inner corner of the eye	either of the corners of the eye where the upper and lower eyelids meet