| Question | Answer |
| Across, beyond, through | Trans |
| Especially of a railroad line crossing a continent | Transcontinental |
| Move from one place to another | Transfer |
| The process or a period of changing from one state of condition to another | Transition |
| One | Uni |
| Of an action or decision performed by or affecting only one person, group or country involved in a particular situation | Unilateral |
| A cycle with a single wheel | Unicycle |
| Simultaneous performance of action or utterance of speech | Unison |
| Not, opposite, lacking | Un |
| Of a text not cut or shortened; complete | Unabridged |
| Not based on or behaving according to the principles of equality and justice | Unfair |
| Not based on or conforming to what is generally done or believed | Unconventional |
| Apart | Se |
| To withdraw formally from membership of a federal union, alliance or organization | Secede |
| To keep someone away from other people | Seclude |
| The action of withdrawing formally from membership of a federation or body, especially a political state | Secession |
| Under, lower, inferior | Sub |
| To cause to be under water | Submerge |
| Below the usual or required standard | Substandard |
| Below an average level | Subpar |
| Higher (quantity or quality) | Super |
| Higher in rank, status, or quality | Superior |
| Involving a speed greater than that of sound | Supersonic |
| Unnecessary, especially through being more than enough | Superluous |
| Before, in front of | Pro |
| A forecast of the likely cause of a disease/outcome of a situation | Prognosis |
| A separate introductory section of a literary or musical work | Prologue |
| To put forward plan or idea for consideration | Propose |
| Again | Re |
| To wind a tape of film back to the beginning | Rewind |
| To recover in value, amount of strength after a previous decline | Rebound |
| To play back again or repeat | Replay |
| Back, backward | Retro |
| Especially of legislation taking effect from a date in the past | Retroactive |
| To go back to an earlier state, typically a worse one | Retrogress |
| A survey or review of a past course of events or period of time | Retrospect |
| No, not, without | Non |
| Spoken or written words that have no meaning or make no sense | Nonsense |
| A person who does not believe in something | Nonbeliever |
| Of a place in which smoking tobacco is not permitted | Nonsmoking |
| In the way, against | Ob |
| Hard to make out or define | Obscure |
| A thing that blocks one's way or prevents or hinders progress | Obstacle |
| Say something to express one's disapproval of or disagreement with something | Object |
| All | Omni |
| Having unlimited power; able to do anything | Omnipotent |
| Knowing everything | Omniscient |
| An animal or person that eats food of both plant and animal origin | Omnivore |
| Bad, ill, wrong | Mal |
| Dissatisfied and rebellious | Malcontent |
| Intending or intended to do harm | Malicious |
| Improper, illegal or negligent professional activity or treatment | Malpractice |
| Bad, wrong, hate | Mis |
| To behave badly | Misbehave |
| An error in printed text | Misprint |
| A wrong or inaccurate name | Misnomer |
| One, alone | Mono |
| A long speech by one person | Monologue |
| Containing or using only one color | Monochromatic |
| The doctrine or belief that there is only one God | Monotheism |
