There are 13 words that start with 'coar'.
| coarse | coarsen | coarser |
| coarsely | coarsens | coarsest |
| coarctate | coarsened | coarseness |
| coarsening | coarctation | coarctations |
| coarsenesses | ||
Note: These 13 words that start with 'coar' are found from the USA & Canada version of the tournament Scrabble word list.