| month in, month out | | | |
| month of Sundays | | | |
| moonlight flit | | | |
| moral bankruptcy | | | |
| moral high ground | | | |
| moral low ground | | | |
| morally bankrupt | | | |
| moral of the story | | | |
| more cry than wool | | | |
| more equal | | | |
| more often than not | | | |
| more's the pity | | | |
| more than meets the eye | | | |
| more than one bargained for | | | |
| more than you can shake a stick at | | | |
| morning person | | | |
| most an end | | | |
| mother hen | | | |
| mother-hive | | | |
| Mother Hubbard | | | |
| mother lode | | | |
| mother of all | | | |
| motion of someone's ocean | | | |
| mouth breather | | | |
| mouthful of marbles | | | |
| mouth the words | | | |
| move furniture | | | |
| move heaven and earth | | | |
| move house | | | |
| move on | | | |
| move one's body | | | |
| move out | | | |
| move someone to tears | | | |
| move the goalposts | | | |
| move the needle | | | |
| move the yardsticks | | | |
| move through the gears | | | |
| move up in the world | | | |
| movie jail | | | |
| much ado about nothing | | | |
| much less | | | |
| much of a muchness | | | |
| muddle along | | | |
| muddy the waters | | | |
| muddy up | | | |
| mud fence | | | |
| mud monkey | | | |
| mugged by reality | | | |
| mug's game | | | |
| mukluk telegraph | | | |
| mum's the word | | | |
| murderers' row | | | |
| murder will out | | | |
| mush up | | | |
| music to someone's ears | | | |
| mutual admiration society | | | |
| my arse | | | |
| my bad | | | |
| my eye | | | |
| my foot | | | |
| my skull's afly | | | |
| my way or the highway | | | |
| my word | | | |
Mac + Safari
iPhone + iPad
Google Chrome
Mozilla Firefox
Opera
Microsoft Edge