The word "utterest" is spelled with a double "t" in the middle, despite the fact that it is pronounced with just one "t." This can be explained through the use of IPA phonetic transcription, which shows that the word is pronounced /ˈʌtərəst/ without any emphasis on the second "t." The spelling likely comes from the word's origin in Old English, where the double "t" was used to represent a sound that has since changed in pronunciation. Despite its odd spelling, "utterest" remains a valid word in the English language.
The word utterest is derived from the root word utter. Utter can be traced back to the Old English word utera, meaning outer or exterior. Over time, it evolved to mean to put forth or to express. The addition of the suffix -est forms the superlative degree, making utterest mean most complete or most extreme.