lowercase vs uppercase

lowercase and uppercase both are nouns.

Word	Noun	Adjective	Verb	Adverb
lowercase	Yes	Yes	No	No
uppercase	Yes	Yes	No	No

lowercase (noun)	uppercase (noun)
the characters that were once kept in bottom half of a compositor's type case	one of the large alphabetic characters used as the first letter in writing or printing proper names and sometimes for emphasis

lowercase (adjective)	uppercase (adjective)
relating to small (not capitalized) letters that were kept in the lower half of a compositor's type case	relating to capital letters which were kept in the top half of a compositor's type case