What does nocuous mean?
Nocuous is a formal adjective meaning harmless or unlikely to cause harm. It can describe a substance, organism, action, influence, or other thing that poses no danger. Because the word is uncommon, it often sounds precise, elevated, or deliberately distinctive in contemporary English, although its meaning is straightforward. Writers commonly choose innocuous or harmless instead, while noxious provides an especially useful contrast: noxious means harmful or poisonous, whereas nocuous means the reverse. The word ultimately comes from a Latin family associated with nocere, “to hurt,” which also underlies words such as noxious and innocent. Nocuous is therefore memorable not only for its relatively unusual form but also for its unusual position within that family: it names something that does not hurt.
adjectiveHarmless or unlikely to cause harm. It is a formal and relatively uncommon synonym for harmless or innocuous.
- Harmless; unlikely or unable to cause harm.
"The researcher emphasized that the compound was entirely nocuous and posed no danger to the environment."
"The apparent threat proved to be nocuous."
"Doctors assured the public that the vaccine was safe and nocuous."
A rare formal word that means the opposite of noxious: something nocuous is, by definition, not dangerous.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of nocuous
Nocuous comes from Latin nocuus, meaning “harmless,” a word associated with nocere, “to hurt.” The same root appears in English borrowings and derivatives such as noxious and innocuous, as well as in innocent. The adjective entered English as a learned, formal term and remains much less common than harmless and innocuous.
Related word forms
How nocuous is actually used
Nocuous is formal and relatively uncommon. In modern general writing, harmless or innocuous is usually more natural; noxious is its clearest contrast.
Easily confused with nocuous
Nocuous means harmless, whereas noxious means harmful, poisonous, or likely to cause injury.