There are 18 words that start with 'quat'.
| quate | quatre |
| quatres | quatorze |
| quatrain | quatorzes |
| quatrains | quaternary |
| quaternion | quaternity |
| quatrefoil | quaternions |
| quatrefoils | quaternaries |
| quaternities | quattrocento |
| quattrocentos | quatercentenary |
Note: These 18 words that start with 'quat' are found from the USA & Canada version of the tournament Scrabble word list.