There are 30 13-letter words that start with 'multi'.
Note: These 30 13-letter words that start with 'multi' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with multip, multic, multis, multif, multit, multil, multim, multiv, multib, multie, multin, multid, multir, multia, multig, multih, multiu, multiw, multij, multio, multiy.
8-letter words start with 'multi' (10)