| Certain m.p.g. rating: Abbr. | 28 |
| Certain machetes | 16 |
| Certain machinist | 17 |
| Certain machinist's activity | 32 |
| Certain madonnas | 16 |
| Certain madrileña | 20 |
| Certain madrileñas | 21 |
| Certain magazines | 17 |
| Certain mah-jongg player | 24 |
| Certain maid | 12 |
| Certain maid or man | 19 |
| Certain mail cars: Abbr. | 24 |
| Certain mail destination: Abbr. | 31 |
| Certain mail: abbr. | 19 |
| Certain mailing addresses | 25 |
| Certain main | 12 |
| Certain main trunk | 18 |
| Certain major | 13 |
| Certain major leaguer | 21 |
| Certain Major Leaguer (Abbr.) | 29 |
| Certain Major Leaguer of old | 28 |
| Certain major-league baseballer | 31 |
| Certain major-leaguer, to a letter writer? | 42 |
| Certain majority | 16 |
| Certain male | 12 |
| Certain male chicken | 20 |
| Certain male deer | 17 |
| Certain male doll | 17 |
| Certain male sheep | 18 |
| Certain man | 11 |
| Certain man of the cloth | 24 |
| Certain Manhattanite | 20 |
| Certain Manitoba Indian | 23 |
| Certain maps | 12 |
| Certain marble | 14 |
| Certain marbles | 15 |
| Certain March days | 18 |
| Certain marcher | 15 |
| Certain marcher in a parade | 27 |
| Certain marine biologist's test? | 36 |
| Certain marine mammal | 21 |
| Certain Marine rank | 19 |
| Certain marine vessel | 21 |
| Certain marital contracts, briefly | 34 |
| Certain marked-down item: Abbr. | 31 |
| Certain marksmanship event | 26 |
| Certain marquis's activity | 30 |
| Certain marsupials, informally | 30 |
| Certain mason | 13 |
| Certain mass transit route | 26 |
| Certain Massachusetts university | 32 |
| Certain master | 14 |
| Certain master's area | 25 |
| Certain matériel, for short | 30 |
| Certain match ends: abbr. | 25 |
| Certain match results | 21 |
| Certain matchmaker | 18 |
| Certain mater | 13 |
| Certain math | 12 |
| Certain math class | 18 |
| Certain math instructor | 23 |
| Certain math number | 19 |
| Certain math sign | 17 |
| Certain math units | 18 |
| Certain mathematical planes | 27 |
| Certain mathematicians | 22 |
| Certain mattress embroidery | 27 |
| Certain MDs | 11 |
| Certain means of communication | 30 |
| Certain means: Abbr. | 20 |
| Certain measured dose | 21 |
| Certain measurement | 19 |
| Certain measurement: Abbr. | 26 |
| Certain measurements | 20 |
| Certain mechanic | 16 |
| Certain med. reading | 20 |
| Certain med. test | 17 |
| Certain medalist | 16 |
| Certain mediators | 17 |
| Certain medical facility | 24 |
| Certain medical plans: Abbr. | 28 |
| Certain medical student | 23 |
| Certain medical symptoms | 24 |
| Certain medical test | 20 |
| Certain medics: Abbr. | 21 |
| Certain medieval combatant | 26 |
| Certain medieval tales | 22 |
| Certain meditator | 17 |
| Certain meeting | 15 |
| Certain meeting leader | 22 |
| Certain melon | 13 |
| Certain member of an Islamic people | 35 |
| Certain member of the Slavic people | 35 |
| Certain member of the wind section | 34 |
| Certain members of Indian royalty | 33 |
| Certain memorial tattoo | 23 |
| Certain men at eve | 18 |
| Certain menagerie | 17 |
| Certain Mennonites | 18 |
| Certain mental construct | 24 |