The word "formulist" is spelled with the letter "u" and not "o" due to its pronunciation. The IPA phonetic transcription for this word is /ˈfɔːmjʊlɪst/ which highlights the stressed syllable as "mu" where "u" is pronounced like "you". The "o" sound in "formula" is replaced by "u" to represent the correct sound. "Formulist" refers to a person who formulates or creates formulas, particularly in science or mathematics. It is important to spell words correctly for effective communication and comprehension.