The correct spelling of the word "most umber" is actually "moustache". The phonetic transcription for this word is /mʌˈstæʃ/. The word is derived from French, where it is spelled "moustache". The "ou" combination is often used in French to represent the "oo" sound in English. In English, "ou" is usually pronounced as "ow", as in "mouse" or "house". However, in "moustache", the "ou" is pronounced as "u", making the phonetic spelling "mus-tash".