There are 3 14-letter words that start with 'slu'.
| sluggardnesses | sluggishnesses | 
| sluttishnesses | |
Note: These 3 14-letter words that start with 'slu' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with slum, slug, slur, slus, slub, slut, slui, slud, sluf, slun, slue.
4-letter words start with 'slu' (6)