There are 14 words that start with 'castr'.
| castrate | castrati | castrato |
| castrated | castrater | castrates |
| castrator | castratos | castraters |
| castrating | castration | castrators |
| castratory | castrations | |
Note: These 14 words that start with 'castr' are found from the USA & Canada version of the tournament Scrabble word list.