poisonous

comparative more poisonous · superlative most poisonous

1. Containing sufficient poison to be dangerous to touch or ingest.

   While highly poisonous to dogs, this substance is completely harmless if ingested by humans.

   2 more examples

   Nor taint-worm ſhall infect the yeaning herds / Nor penny-graſs, nor ſpearwort's poiſ'nous leaf.

   1757, John Dyer, “Book I”, in The Fleece: A Poem […] , London: R. and J. Dodsley, page 40

   I had picked a mushroom so poisonous that particles of it, stuck to my fingers and accidentally swallowed, could have made me deathly ill, and a piece the size of my thumb could have killed me.

   2003, Charles L. Fergus, Common Edible and Poisonous Mushrooms of the Northeast, Stackpole Books, →ISBN, page 77

   Synonyms: poisoned, toxic, venomous, attery · Antonyms: nonpoisonous, unpoisonous

2. proscribedsometimesOf an animal such as a snake or spider, or parts of its body: producing a toxin intended for defensive or offensive use which is usually injected into an enemy or prey by biting or stinging; hence, of a bite or sting: injecting poison.

   Poisonous snakes should only be handled by experienced professionals.

   5 more examples

   SERPENT … either that which is not poiſonous: or that which is counted poiſonous, having two long, hollow, moveable teeth, …

   1668, John Wilkins, chapter V, in An Essay Towards a Real Character, And a Philosophical Language., London: Printer to the Royal Society, page 161

   The Cencoatl (o), which is alſo a poiſonous ſnake, is about five feet long, and eight inches round at the thickeſt part.

   1787, F.S. Clavigero, The History of Mexico, London: G. G. J. and J. Robinson, page 60

   Evidently the first thing to ascertain is whether the case is really that of a bite by a poisonous snake…

   1895, Leonhard Stejneger, The Poisonous Snakes of North America, Washington: U.S. Government Printing Office, page 475

   The characteristics which separate the dangerously venomous groups from their non-poisonous relatives are emphasized.

   1963, United States. Navy Department. Naval Operations Office, Poisonous Snakes of the World, U.S. Government Printing Office, page 29

   These antivenins make living near poisonous spiders much safer.

   2002, B. Kalman and K. Smithyman, The Life Cycle of a Spider, Crabtree Publishing Company, page 31

3. figurativelyNegative, harmful.

   He didn't want to end up like his grandfather, bitter and intractable, consumed in his hatred like an addict on haze — a poisonous attitude that would possess him all his remaining years.

   2013, Kylie Griffin, Allegiance Sworn, Penguin, →ISBN

   Synonyms: toxic