The spelling of the word "most explicatory" follows the standard English rules for spelling. The word is pronounced as /moʊst ɪksplɪkətɔːri/ in IPA phonetic transcription. The first syllable "most" is pronounced with a long "o" sound, followed by the "s" sound. The second syllable "ex-" is pronounced with a short "e" sound, followed by the "ks" sound. The third syllable "-pli-" is pronounced with a short "i" sound, followed by the "k" sound. The final syllable "-tory" is pronounced with a long "o" sound, followed by the "r" sound.
There is no specific etymology for the phrase "most explicatory" as it is not a commonly used or recognized term in English. "Explicatory" itself is a derivative of the word "explicate", which means to analyze or make the meaning of something clear. However, "most explicatory" would not typically be used in English.