There are 14 words that start with 'calum'.
| calumet | calumny | 
| calumets | calumnies | 
| calumniate | calumnious | 
| calumniated | calumniates | 
| calumniator | calumniating | 
| calumniation | calumniators | 
| calumniously | calumniations | 
Note: These 14 words that start with 'calum' are found from the USA & Canada version of the tournament Scrabble word list.