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.