There are 9 words that start with 'copo'.
| copout | copouts | 
| copolymer | copolymers | 
| copolymeric | copolymerize | 
| copolymerized | copolymerizes | 
| copolymerizing | |
Note: These 9 words that start with 'copo' are found from the USA & Canada version of the tournament Scrabble word list.