The word "Millborne" is phonetically spelled as /ˈmɪlbɔːrn/. The first syllable "Mill" is pronounced as /mɪl/, which refers to a building that grinds grains into flour. The second syllable "borne" is pronounced as /bɔːrn/, which rhymes with the word "corn." The correct spelling of this word is a compound word consisting of "Mill" and "borne." Thus, the spelling should be two separate words- "Mill" and "borne." The word is often misspelled as "Millbourne" or "Millburn."