| Term | Definition |
| macabre | horrible; gruesome |
| Machiavellian | deceitful; tricky |
| machination | evil design |
| macroscopic | visible to the naked eye |
| maelstrom | whirlpool |
| magnanimous | generous |
| magnate | important person in any field |
| magnitude | size; extent |
| maim | to cripple; to deprive of the use of some part of the body |
| maladroit | clumsy; unskillful; awkward |
| malady | disease; illness |
| malaise | discomfort; uneasiness |
| malapropism | word humorously misused |
| malcontent | one who is dissatisfied |
| malediction | curse |
| malefactor | wrong-doer; villain |
| malevolent | showing ill will or hatred; very dangerous, harmful |
| malfeasance | wrongdoing |
| malicious | spiteful; vengeful |
| malign | to speak badly of |