Source : WordNet®

upper-case letter
     n : 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" [syn: {capital}, {capital
         letter}, {upper case}, {majuscule}] [ant: {small letter}]