The word "most lastword" is not a commonly used term in English. However, it can be spelled using the International Phonetic Alphabet (IPA) as /moʊst lʌst wɜːrd/. The first two syllables are pronounced with a long 'o' sound and a short 'u' sound respectively. The final syllable contains the 'w' and 'r' sounds, followed by a long 'o' and a short 'u' sound. While this word may not have much practical use, understanding IPA can be useful for communicating pronunciation accurately.