| Term | Definition |
| monologue | A long speech made by one performer or by one person in a group. |
| monarch(1) | A person who rules a kingdom or empire; a king or queen, emperor or empress. |
| monarch(2) | A large black and orange American butterfly. |
| monogram | A design composed of letters, usually the first letter of a name. |
| monopoly(1) | Exclusive control of the trade in some item or service. |
| monopoly(2) | Sole ownership or control of anything. |
| monolith(1) | A large block or stone. |
| monolith(2) | A large organization that acts as a single unit. |
| unanimous | Being in complete agreement. |
| unilateral | One-sided; done by or affecting one person, group, or country, etc., and not another. |
| duplex | A dwelling with two living units. |
| duplicate | To make an identical copy or double of something; to repeat. |
| bilateral(1) | Having two sides. |
| bilateral(2) | Made between two persons or groups. |
| bipartisan | Involving two political parties. |
| bisect | To divide into two equal parts. |