There are 98 words that start with 'extra'.
Note: These 98 words that start with 'extra' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with extrav, extrac, extrap, extrad, extral, extran, extram, extras, extrao, extrab, extraj, extrae, extrag, extrah, extrat, extrau.