There are 17 words that start with 'exos'.
| exosmic | exosmose | exospore |
| exosmoses | exosmosis | exosmotic |
| exosphere | exospores | exosporia |
| exostoses | exostosis | exospheres |
| exospheric | exosporium | exoskeletal |
| exoskeleton | exoskeletons | |
Note: These 17 words that start with 'exos' are found from the USA & Canada version of the tournament Scrabble word list.