There are 16 words that start with 'pinna'.
| pinna | pinnae | pinnal | 
| pinnas | pinnace | pinnate | 
| pinnaces | pinnacle | pinnated | 
| pinnacled | pinnacles | pinnately | 
| pinnation | pinnacling | pinnatifid | 
| pinnations | ||
Note: These 16 words that start with 'pinna' are found from the USA & Canada version of the tournament Scrabble word list.