Tithonicity is a term used in astronomy to define the ancient period of the solar system, specifically between the Hadean and the Phanerozoic eons. The spelling of this word can be explained using IPA phonetic transcription, where it is pronounced as /tɪθə'nɒsɪti/. The first syllable of the word is pronounced as "TIH-", followed by the stressed syllable "tho", which is pronounced as "THOW". The last syllable of the word, "-city", is pronounced as "SIT-ee". The correct pronunciation of this term is important in scientific discussions about the history and evolution of our solar system.
That property of light by which it produces chemical effects.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.