There are 21 words that start with 'cool'.
| cool | cools | cooly |
| cooled | cooler | coolie |
| coolly | coolth | coolant |
| coolers | coolest | coolies |
| cooling | coolish | coolths |
| coolants | cooldown | coolness |
| cooldowns | coolheaded | coolnesses |
Note: These 21 words that start with 'cool' are found from the USA & Canada version of the tournament Scrabble word list.