- nihilist: An advocate of the doctrine that nothing either exists or can be known.
- nil: Nothing
- nimble: Light and quick in motion or action.
- nit: The egg of a louse or some other insect.
- nocturnal: Of or pertaining to the night.
- noiseless: Silent.
- noisome: Very offensive, particularly to the sense of smell.
- noisy: Clamorous.
- nomad: Having no fixed abode.
- nomic: Usual or customary.
- nominal: Trivial.
- nominate: To designate as a candidate for any office.
- nomination: The act or ceremony of naming a man or woman for office.
- nominee: One who receives a nomination.
- non-combatant: One attached to the army or navy, but having duties other than that of fighting.
- non-existent: That which does not exist.
- non-resident: Not residing within a given jurisdiction.
- nonchalance: A state of mind indicating lack of interest.
- nondescript: Indescribable.
- nonentity: A person or thing of little or no account.
- nonpareil: One who or that which is of unequaled excellence.
- norm: A model.
- normalcy: The state of being normal.
- Norman: Of or peculiar to Normandy, in northern France.
- nostrum: Any scheme or recipe of a charlatan character.
- noticeable: Perceptible.
- notorious: Unfavorably known to the general public.
- novellette: A short novel.
- novice: A beginner in any business or occupation.
- nowadays: In the present time or age.
- nowhere: In no place or state.
- noxious: Hurtful.
- nuance: A slight degree of difference in anything perceptible to the sense of the mind.
- nucleus: A central point or part about which matter is aggregated.
- nude: Naked.
- nugatory: Having no power or force.
- nuisance: That which annoys, vexes, or irritates.
- numeration: The act or art of reading or naming numbers.
- numerical: Of or pertaining to number.
- nunnery: A convent for nuns.
- nuptial: Of or pertaining to marriage, especially to the marriage ceremony.
- nurture: The process of fostering or promoting growth.
- nutriment: That which nourishes.
- nutritive: Having nutritious properties.
- oaken: Made of or from oak.
- oakum: Hemp-fiber obtained by untwisting and picking out loosely the yarns of old hemp rope.
- obdurate: Impassive to feelings of humanity or pity.
- obelisk: A square shaft with pyramidal top, usually monumental or commemorative.
- obese: Exceedingly fat.
- obesity: Excessive fatness.