adjective. Harmful to living things; injurious to health.

adjective. Harmful to the mind or morals; corrupting.

Hurtful; harmful; baneful; pernicious: as, noxious vapors; noxious animals.

Guilty; criminal.

Synonyms Noxious, Pernicious, Noisome, pestiferous, pestilent, poisonous, mischievous, corrupting. That which is noxious is actively and energetically harmful. That which is pernicious is as actively destructive. Noisome and noxious were once essentially the same (see Job xxxi. 40, margin; Ps. xci. 3; Ezek. xiv. 21), but noisome now snggests primarily foulness of odor, with a secondary noxiousness to health. Unwholesome vapors that do not offend the sense of smell would now hardly be called noisome.

adjective. Hurtful; harmful; baneful; pernicious; injurious; destructive; unwholesome; insalubrious; ; pernicious; corrupting to morals.

adjective. Guilty; criminal.

adjective. Harmful; injurious.

adjective. injurious to physical or mental health

"The good news, indeed, coming from this location, about 30 miles northwest of the previous Long Beach location here in the city of Los Angeles, L.A. firefighters, including our hazardous materials experts, have gone into a three-story AT&T telephone company switching office where they discovered approximately 10 persons who had become ill after being exposed to what they described as noxious fumes."

baneful  corrupting  deadly  degrading  pernicious  

obnoxious  

corrosive  dank  deleterious  fetid  foul  

abhorrent  abominable  also  bad  bad for