noxious

Something noxious is harmful and could be even fatal — whether it is colorless, odorless, and invisible like carbon monoxide, or dark, strong-smelling, and obvious, like black smoke from a fire. People are called noxious too when they hurt others with cruelty or mental anguish.

English and Latin roots for noxious are related to the meanings of "harm," "damage," and "injury." While obnoxious might come to mind when seeing the word noxious, obnoxious is a much less damaging adjective to describe someone annoying. Most uses for noxious involve real physical or emotional damage unless the word is used in exaggeration. Examples range from "the noxious gas fumes made the dog pass out" to "his cologne was so noxious I had to exit the elevator and take the stairs."

Definitions of noxious
  1. adjective
    injurious to physical or mental health
    noxious chemical wastes”
    noxious ideas”
    Synonyms:
    harmful
    causing or capable of causing harm
    baneful, deadly, pernicious, pestilent
    exceedingly harmful
    corrupting, degrading
    harmful to the mind or morals
    vesicant, vesicatory
    causing blisters
    toxic
    of or relating to or caused by a toxin or poison
    unwholesome
    detrimental to physical or moral well-being
    see moresee less
    Antonyms:
    innocuous
    not injurious to physical or mental health
    harmless
    not causing or capable of causing harm
    innoxious
    having no adverse effect
    show more antonyms...
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