| A | B |
| MONOS | <G. "one" |
| monologue | a long speech made by one performer or by one person in a group |
| monarch | a person who rules a kingdom or empire; a king or queen, emperor or empress |
| monarch2 | a large black & orange American butterfly2 |
| monogram | a design composed of letters, usually the first letter of a name |
| monopoly | exclusive control of the trade in some item or service |
| monopoly2 | sole ownership of control of anything2 |
| monolith | a large block of stone |
| monolith2 | a large organization that acts as a single unit2 |
| UNUS | <L. "one" |
| unanimous | being in complete agreement |
| unilateral | one-sided; done by or affecting one person, gruop, or country, etc., and not another. |
| DUO | <L. "two" |
| DUPLEX | <L. "twofold" |
| duplex | a dwelling with two living units |
| duplicate | to make an identical copy or double of something; to repeat |
| BI | <L. "two" |
| bilateral | having two sides |
| bilateral2 | made between two persons or groups2 |
| bipartisan | involving two political parties |
| bisect | to divide into two equal parts |