| Term | Definition |
| naut | to sail |
| astronaut | someone who travels and works in a spacecraft |
| cosmonaut | from Russia or the former Soviet Union |
| nausea | the feeling that you get when you think you are going to vomit |
| neg | to deny |
| negative | having a bad or harmful effect |
| negotiate | to discuss something in order to reach agreement |
| abnegation | act of not allowing yourself to do something that you want |
| neur | nerve |
| neuro | nerve |
| neurotic | anxious or afraid in an unreasonable way |
| neurosis | mental illness that makes someone very worried |
| noc | night |
| nox | night |
| nocturne | a soft beautiful piece of music |
| nocturnal | an animal that is nocturnal is active at night |
| equinox | one of the times in a year when day and night are equal in length everywhere |
| nom | law, order |
| nomy | law, order |
| astronomy | the science that deals with the material universe beyond the earth's atmosphere |
| economy | thrifty management; frugality in the expenditure or consumption of money, materials, etc |
| binominal | Of or pertaining to two names |