Corpus Christi is a Latin-derived proper noun referring to a religious festival or a city name (notably in Texas and other locales). In English usage it is typically pronounced with a soft initial 'Cor-' and a clear 'Christi' ending, preserving the Latin stress pattern. The phrase is often treated as two capitalized words, with attention to the /k/ start and the /uː/ or /ɔː/ vowel in the first syllable depending on dialect.
Full pronunciation guide