The spelling of the word "most rotted" can be explained using IPA phonetic transcription. The first syllable, "most," is pronounced /moʊst/ with a long "o" sound and a soft "s" sound. The second syllable, "rotted," is pronounced /ˈrɑt̬.əd/ with a short "o" sound followed by a double "t" and a soft "d" sound. Overall, the word "most rotted" is spelled phonetically to accurately represent its pronunciation.