There are 14 words that start with 'aux'.
| auxin | auxins | auxeses |
| auxesis | auxetic | auxinic |
| auxetics | auxiliary | auxotroph |
| auxotrophs | auxotrophy | auxiliaries |
| auxotrophic | auxotrophies | |
Note: These 14 words that start with 'aux' are found from the USA & Canada version of the tournament Scrabble word list.