There are 20 words that start with 'mumm'.
| mumm | mumms |
| mummy | mummed |
| mummer | mummers |
| mummery | mummied |
| mummies | mummify |
| mumming | mummying |
| mummeries | mummichog |
| mummified | mummifies |
| mummichogs | mummifying |
| mummification | mummifications |
Note: These 20 words that start with 'mumm' are found from the USA & Canada version of the tournament Scrabble word list.