The spelling of the word "most acherontic" follows standard English pronunciation rules. The word "most" is spelled as it sounds, with the short "o" sound and the "s" sounding like a "z". "Acherontic" is spelled with the "ch" sound, which is represented in IPA phonetic transcription as /k/, and the "er" sound, represented as /ɛr/. The stress falls on the second syllable, which is indicated with a "ˈ" symbol in IPA. The final "ic" is pronounced with a hard "k" sound, represented as /k/.