adjective nox·ious \ˈnäk-shəs\

: harmful to living things

Full Definition of NOXIOUS

a :  physically harmful or destructive to living beings <noxious waste>
b :  constituting a harmful influence on mind or behavior; especially :  morally corrupting <noxious doctrines>
nox·ious·ly adverb
nox·ious·ness noun

Origin of NOXIOUS

Middle English noxius, from Latin, from noxa harm; akin to Latin nocēre to harm, nec-, nex violent death, Greek nekros dead body
First Known Use: 15th century

Synonym Discussion of NOXIOUS

pernicious, baneful, noxious, deleterious, detrimental mean exceedingly harmful. pernicious implies irreparable harm done through evil or insidious corrupting or undermining <the claim that pornography has a pernicious effect on society>. baneful implies injury through poisoning or destroying <the baneful notion that discipline destroys creativity>. noxious applies to what is both offensive and injurious to the health of a body or mind <noxious chemical fumes>. deleterious applies to what has an often unsuspected harmful effect <a diet found to have deleterious effects>. detrimental implies obvious harmfulness to something specified <the detrimental effects of excessive drinking>.

Other Ecology Terms

Malthusian, anthropogenic, biomass, carbon footprint, crepuscular, niche, sere, symbiosis, taiga, tundra
NOXIOUS Defined for Kids


adjective nox·ious \ˈnäk-shəs\

Definition of NOXIOUS for Kids

:  causing harm <noxious fumes>
Medical Dictionary


adjective nox·ious \ˈnäk-shəs\

Medical Definition of NOXIOUS

:  physically harmful or destructive to living beings <noxious wastes>


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