There are 147 13-letter words that start with 'mi'.
Note: These 147 13-letter words that start with 'mi' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with mis, mic, mil, min, mid, mit, mir, mim, mig, mia, mix, mik, miz, mif, mio, mib, mie, mih, mij, miq, mip.
3-letter words start with 'mi' (9)