scleritis vs redness

scleritis and redness both are nouns.

Word	Noun	Adjective	Verb	Adverb
scleritis	Yes	No	No	No
redness	Yes	No	No	No

As nouns, redness is a hypernym of scleritis; that is, redness is a word with a broader meaning than scleritis:

scleritis: inflammation of the sclera
redness: a response of body tissues to injury or irritation; characterized by pain and swelling and redness and heat

Other hypernyms of scleritis include inflammation, rubor.

scleritis (noun)	redness (noun)
inflammation of the sclera	red color or pigment; the chromatic color resembling the hue of blood
	a response of body tissues to injury or irritation; characterized by pain and swelling and redness and heat