Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
uppercase is a noun and adjective meaning "one of the large alphabetic characters used as the first letter in writing or printing proper names and sometimes for emphasis". It carries 2 recorded senses.
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”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for uppercase come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.