plainness vs appearance

plainness and appearance both are nouns.

Word	Noun	Adjective	Verb	Adverb
plainness	Yes	No	No	No
appearance	Yes	No	No	No

As nouns, appearance is a hypernym of plainness; that is, appearance is a word with a broader meaning than plainness:

Other hypernyms of plainness include visual aspect.

As nouns, appearance is a hypernym of plainness; that is, appearance is a word with a broader meaning than plainness:

Other hypernyms of plainness include visual aspect.

plainness (noun)	appearance (noun)
the appearance of being plain and unpretentious	the act of appearing in public view
an appearance that is not attractive or beautiful	formal attendance (in court or at a hearing) of a party in an action
clarity as a consequence of being perspicuous	pretending that something is the case in order to make a good impression
the state of being unmixed with other material	outward or visible aspect of a person or thing
	a mental representation
	the event of coming into sight