erythema vs windburn

erythema and windburn both are nouns.

Word	Noun	Adjective	Verb	Adverb
erythema	Yes	No	No	No
windburn	Yes	No	No	No

As nouns, windburn is a hyponym of erythema; that is, windburn is a word with a more specific, narrower meaning than erythema:

erythema: abnormal redness of the skin resulting from dilation of blood vessels (as in sunburn or inflammation)
windburn: redness and irritation of the skin caused by exposure to high-velocity wind

Other hyponyms of erythema include erythema multiforme, erythema nodosum, hickey, love bite, erythema solare, sunburn.

erythema (noun)	windburn (noun)
abnormal redness of the skin resulting from dilation of blood vessels (as in sunburn or inflammation)	redness and irritation of the skin caused by exposure to high-velocity wind