There are 17 words that start with 'diar'.
| diary | diarchy | diaries |
| diarist | diarchic | diarists |
| diarrhea | diarchies | diaristic |
| diarrheal | diarrheas | diarrheic |
| diarrhoea | diarrhetic | diarrhoeas |
| diarthroses | diarthrosis | |
Note: These 17 words that start with 'diar' are found from the USA & Canada version of the tournament Scrabble word list.