The spelling of the word "Pertusion" can be explained using IPA phonetic transcription. The word is pronounced as pərˈtuʒən, where the first syllable is stressed, and the "u" is pronounced as a schwa sound. The second syllable is pronounced with the "t" and "s" sounds blending together to form a "ʃ" sound. The word is spelled with "p-e-r-t-u-s-i-o-n," with "ion" at the end denoting a noun formed from a verb. The meaning of "pertusion" is unclear as it is not a commonly used word.