| A | B |
| monos | 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 |
| monogram | a design composed of letters, usually the first in a name |
| monopoly | xclusive control of the trade in some item or service |
| monolith | a large block of stone |
| unus | one |
| unanimous | being in complete agreement |
| unilateral | one-sided |
| duo | two |
| duplex | twofold |
| duplex | a dwelling with two living units |
| duplicate | to make an identical copy or double of something |
| bi | two < L |
| bilateral | having two sides |
| bipartisan | involving two political parties |
| bisect | to divide into two equal parts |