There are 14 words that start with 'phren'.
| phrenic | phrensy | 
| phrenetic | phrenitis | 
| phrensied | phrensies | 
| phrenology | phrensying | 
| phrenitides | phrenitises | 
| phrenologies | phrenologist | 
| phrenological | phrenologists | 
Note: These 14 words that start with 'phren' are found from the USA & Canada version of the tournament Scrabble word list.