There are 373 11-letter words that start with 'su'.
Note: These 373 11-letter words that start with 'su' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with sub, sup, sur, sul, sun, suc, sum, sus, suf, sug, sud, sui, sua, sut, sue, suk, suz, suq.
3-letter words start with 'su' (7)