There are 14 words that start with 'cotr'.
| cotrustee | cotransfer |
| cotrustees | cotransduce |
| cotransfers | cotransport |
| cotransduced | cotransduces |
| cotransports | cotransducing |
| cotransported | cotransduction |
| cotransporting | cotransductions |
Note: These 14 words that start with 'cotr' are found from the USA & Canada version of the tournament Scrabble word list.