There are 15 words that start with 'parall'.
| parallax | parallel |
| parallels | parallaxes |
| paralleled | parallactic |
| paralleling | parallelism |
| parallelled | parallelisms |
| parallelling | parallelogram |
| parallelepiped | parallelograms |
| parallelepipeds | |
Note: These 15 words that start with 'parall' are found from the USA & Canada version of the tournament Scrabble word list.