There are 20 7-letter words that start with 'slu'.
| slubbed | slubber | sludged | sludges | 
| sluffed | slugged | slugger | sluiced | 
| sluices | slumber | slumgum | slumism | 
| slummed | slummer | slumped | slurban | 
| slurped | slurred | slushed | slushes | 
Note: These 20 7-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)