There are 16 words that start with 'echin'.
| eching | echini | 
| echinus | echinate | 
| echinoid | echinacea | 
| echinated | echinoids | 
| echinaceas | echinoderm | 
| echinococci | echinoderms | 
| echinococcus | echinococcoses | 
| echinococcosis | echinodermatous | 
Note: These 16 words that start with 'echin' are found from the USA & Canada version of the tournament Scrabble word list.