There are 15 words that start with 'sack'.
| sack | sacks | sacked | 
| sacker | sackbut | sackers | 
| sackful | sacking | sackbuts | 
| sackfuls | sackings | sacklike | 
| sacksful | sackcloth | sackcloths | 
Note: These 15 words that start with 'sack' are found from the USA & Canada version of the tournament Scrabble word list.