There are 12 8-letter words that start with 'blac'.
| blackboy | blackcap | blackens | blackest | 
| blackfin | blackfly | blackgum | blacking | 
| blackish | blackleg | blackout | blacktop | 
Note: These 12 8-letter words that start with 'blac' are found from the USA & Canada version of the tournament Scrabble word list.