There are 11 words that start with 'columb'.
| columbic | columbary | columbine | 
| columbite | columbium | columbaria | 
| columbines | columbites | columbiums | 
| columbaries | columbarium | |
Note: These 11 words that start with 'columb' are found from the USA & Canada version of the tournament Scrabble word list.