CORESIAN is a word that is often misspelled due to its unfamiliarity. The correct spelling of CORESIAN is [kɔːrɛʃən]. The first syllable "COR" is pronounced with the open-mid back unrounded vowel, represented by [ɔː]. The second syllable "ES" is pronounced with the e-like sound, represented by [ɛ]. The final syllable "IAN" is pronounced with the schwa sound, represented by [ə], followed by the consonant "n". The correct spelling and pronunciation of CORESIAN will enhance effective communication, both verbal and written.