superscription vs inscription

superscription and inscription both are nouns.

Word	Noun	Adjective	Verb	Adverb
superscription	Yes	No	No	No
inscription	Yes	No	No	No

As nouns, inscription is a hypernym of superscription; that is, inscription is a word with a broader meaning than superscription:

superscription: the activity of superscribing
inscription: the activity of inscribing (especially carving or engraving) letters or words

As nouns, inscription is a hypernym of superscription; that is, inscription is a word with a broader meaning than superscription:

superscription: an inscription written above something else
inscription: letters inscribed (especially words engraved or carved) on something

Other hypernyms of superscription include lettering.

superscription (noun)	inscription (noun)
the activity of superscribing	the activity of inscribing (especially carving or engraving) letters or words
an inscription written above something else	letters inscribed (especially words engraved or carved) on something
	a short message (as in a book or musical work or on a photograph) dedicating it to someone or something