There are 12 words that start with 'koo'.
kook | kooks | kooky |
koodoo | kookie | koodoos |
kookier | kookiest | kookiness |
kookaburra | kookaburras | kookinesses |
Note: These 12 words that start with 'koo' are found from the USA & Canada version of the tournament Scrabble word list.