The word "Festennine" is a unique and uncommon spelling. Using the International Phonetic Alphabet (IPA) transcription, it can be broken down as /ˈfɛstɛnaɪn/. The "f" sound is followed by the "ɛ" vowel sound which is then followed by the "s" and "t" consonant sounds. The "ɛ" sound is repeated again before the "n" sound and finally, the word ends with the "aɪn" sound. The spelling of this word is distinct as it doesn't follow the typical patterns of English spelling.