- poisonous
- poisonous, venomous, virulent, toxic, mephitic, pestilent, pestilential, miasmic, miasmatic, miasmal are comparable when they mean having the properties or the effects of poison (see POISON)Basically poisonous implies that the thing so described will be fatal or exceedingly harmful if introduced into a living organism in sufficient quantities (as by eating, drinking, or inhaling){
the most poisonous of mushrooms
}{poisonous gases
}{[aniline] is also poisonous but by proper chemical manipulation it becomes the parent of many beneficent medicines— Morrison
}In its extended use the term implies extreme noxiousness or perniciousness or power to corrode, rankle, or corrupt{you might condemn us as poisonous of your honor— Shak.
}{the sentence was pronounced ... in a stifling poisonous atmosphere— Conrad
}{secret spreading of poisonous propaganda— Roosevelt
}Venomous applies equally to an animal (as a snake, scorpion, or bee) whose bite or sting introduces a venom (see venom under POISON) into an organism and to the bites, stings, or wounds inflicted by venomous creatures{venomous insects
}{a venomous snake bite
}The term has much extended usage; in this it implies extreme malevolence or destructive malignancy{the most innocent intimacies would not have escaped misrepresentation from the venomous tongues of Roman society— Froude
}{that many of you are frustrated in your ambitions, and undernourished in your pleasures, only makes you more venomous— Mailer
}Virulent implies the destructive or extremely deleterious properties of or as if of a strong poison; it is applied especially to infectious diseases of a particularly malignant or violent form or, somewhat less often, to notably venomous animals{poverty produces outbreaks of virulent infectious disease . . . sooner or later— Shaw
}{one of the most virulent types of the pneumococcus
}{those mosquitoes must have been particularly virulent— Farmer's Weekly
}In extended use the term applies to something particularly violent in its display of an offensive or noxious nature or quality{proceedings . . . dictated by virulent hatred— George Eliot
}{the later stages of the campaign when the rumors became virulent— Michener
}{a toxic goiter
}but more often implies only the character or the properties of a poison and therefore means little more than poisonous{the toxic principle of a drug
}{toxic gases
}{over 200,000 fish were killed by the toxic wastes of one industrial plant— Science
}{a toxic drug
}In its extended use toxic may imply insidious and destructive activity comparable to that of some toxins in the human organism{there are emotionally toxic situations at work in the environment as manifestly injurious ... as physical toxins— McLean
}Mephitic is applicable to something so offensive to the sense of smell that it is or is believed to be actually poisonous{mephitic vapors rising from a swamp
}{the mephitic air of a disused mine
}{the mephitic verdure of the Malay peninsula— Stafford
}Pestilent and pestilential occasionally come close to poisonous in meaning, but they are chiefly used in the extended sense of exceedingly infectious or dangerous to the health, morals, or mental integrity, especially of the group as distinguished from the individual{still fervently espouse the pestilential proposition that the world needs to be saved in a hurry by their own brand of righteousness— Rolo
}{a pestilent land where people died like flies— Maurice Carr
}{grew impatient with such pestilent heresies— Partington
}{blow up the blind rage of the populace, with a continued blast of pestilential libels— Burke
}Miasmic, miasmatic, and miasmal all imply a reference to miasma, or supposedly infectious or deadly emanations from swamps or jungles or from putrescent substances that float in the air{the steaming, rain-drenched, miasmic, leech-filled Sumatran jungle— Rex Lardner
}{the miasmatic northern and northeastern coast— Encyc. Americana
}{the miasmal air of the closed, unventilated room— C. M. Smith
}Of these words only miasmic is common in extended use, where it often comes close to pestilential in implying a power to spread contamination or to poison the minds or souls of the multitude{a miasmic little tale of degeneracy—^. T. Scott
}{miasmic fear of Communism . . . has permeated Houston— Houston Post
}Analogous words: mortal, fatal, lethal, *deadly: *pernicious, baneful, noxious, deleterious, detrimental
New Dictionary of Synonyms. 2014.