There are 18 words that start with 'dors'.
| dors | dorsa | 
| dorsad | dorsal | 
| dorsel | dorser | 
| dorsum | dorsals | 
| dorsels | dorsers | 
| dorsally | dorsiventral | 
| dorsolateral | dorsoventral | 
| dorsiventrally | dorsoventrally | 
| dorsiventrality | dorsoventrality | 
Note: These 18 words that start with 'dors' are found from the USA & Canada version of the tournament Scrabble word list.