| A | B |
| Mono | One |
| uni | one |
| sol | alone, only |
| monologue | a long speech given by a character in a story, movie, play, etc; a speech given by a performer, such as a comedian |
| monotone | a way of talking or singing without raising or lowering the sound of your voice; talking in one tone of voice |
| monotonous | used to describe something that is boring because it is always the same |
| unison | the act of saying of singing something together at the same time; as one |
| unicorn | an imaginary animal that looks like a horse and has one straight horn growing from the middle of its forehead |
| unify | to cause people or things to be joined or brought together |
| unique | used to say that something or someone is unlike anything or anyone else; special or unusual |
| solitude | a state or situation in which you are alone, usually because you want to be |
| solo | a piece of music that is performed by one singer or musician; something that is done without another person |
| solar | of or relating to the sun, which there is only one of |