There are 11 words that start with 'coulo'.
| couloir | coulomb | 
| couloirs | coulombs | 
| coulombic | coulometer | 
| coulometry | coulometers | 
| coulometric | coulometries | 
| coulometrically | |
Note: These 11 words that start with 'coulo' are found from the USA & Canada version of the tournament Scrabble word list.