The correct spelling for the term "most rainbow" is /məʊst ˈreɪnbəʊ/, with the first syllable pronounced as "moh-st" and the second syllable as "rayn-boh". This phrase refers to the most intense and brightest part of a rainbow, which is typically located at the center of the arc. Remember to double-check your spelling before writing, as incorrect spelling can change the meaning of a statement or cause confusion in communication.