There are 17 words that start with 'knoc'.
| knock | knocks | knocked |
| knocker | knockers | knocking |
| knockoff | knockout | knockdown |
| knockless | knockoffs | knockouts |
| knockabout | knockdowns | knockwurst |
| knockabouts | knockwursts | |
Note: These 17 words that start with 'knoc' are found from the USA & Canada version of the tournament Scrabble word list.