There are 16 words that start with 'apt'.
| apt | apter |
| aptly | aptest |
| apteral | apteria |
| apteryx | aptness |
| apterium | apterous |
| aptitude | apteryxes |
| aptitudes | aptnesses |
| aptitudinal | aptitudinally |
Note: These 16 words that start with 'apt' are found from the USA & Canada version of the tournament Scrabble word list.