Proemptosis is a medical term used to describe the early onset of an illness or disease. The spelling of this word may initially appear complicated, but it follows consistent pattern of phonetic pronunciation. The IPA phonetic transcription for this word is /prəʊɛmˈtəʊsɪs/. The first syllable is pronounced as "proh" with a long o sound. The second syllable is pronounced as "em" with a short e sound. The third syllable is pronounced as "toh" with a long o sound. The fourth syllable is pronounced as "sis" with a short i sound.
A happening before, applied to the lunar equation or addition of a day to the calendar every 330 years, and another every 2400 years, in order to prevent the new moon being reckoned as happening a day too soon; the opposite of metemptosis.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.