There are 16 words that start with 'casu'.
| casus | casual | casuals |
| casuist | casually | casualty |
| casuists | casuarina | casuistic |
| casuistry | casualness | casualties |
| casuarinas | casuistical | casuistries |
| casualnesses | ||
Note: These 16 words that start with 'casu' are found from the USA & Canada version of the tournament Scrabble word list.