Meaning of uppercase

(adj) relating to capital letters which were kept in the top half of a compositor's type case; "uppercase letters; X and Y and Z etc"

(noun) one of the large alphabetic characters used as the first letter in writing or printing proper names and sometimes for emphasis; "printers once kept the type for capitals and for small letters in separate cases; capitals were kept in the upper half of the type case and so became known as upper-case letters"