There are 15 words that start with 'phenyl'.
| phenyl | phenyls | 
| phenylic | phenylene | 
| phenylenes | phenylalanine | 
| phenylephrine | phenylalanines | 
| phenylbutazone | phenylephrines | 
| phenylthiourea | phenylbutazones | 
| phenylketonuria | phenylketonuric | 
| phenylthioureas | |
Note: These 15 words that start with 'phenyl' are found from the USA & Canada version of the tournament Scrabble word list.