There are 11 words that start with 'knac'.
| knack | knacks | knacked |
| knacker | knackers | knackery |
| knacking | knackered | knackeries |
| knackwurst | knackwursts | |
Note: These 11 words that start with 'knac' are found from the USA & Canada version of the tournament Scrabble word list.