poisonous

adj

Etymology: From Middle English poisounous, poysonouse. By surface analysis, poison + -ous.

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.”

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

2. Of 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.”

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

3. Negative, 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.”