poisonous

[poi-zuh-nuh s] /ˈpɔɪ zə nəs/

adjective

full of or containing poison:

poisonous air; a poisonous substance.

harmful; destructive:

poisonous to animals; poisonous rumors.

deeply malicious; malevolent:

poisonous efforts.

Origin

1565-75; poison + -ous

Related forms

poisonously, adverb

poisonousness, noun

nonpoisonous, adjective

nonpoisonously, adverb

nonpoisonousness, noun

semipoisonous, adjective

semipoisonously, adverb

unpoisonous, adjective

unpoisonously, adverb

Examples from the web for poisonous

If treatment is obtained soon enough, only a small percentage of those bitten by a poisonous snake die.
One of the poisonous aspects of being on the academic job market is feeling that one can't or shouldn't talk to people about it.
In the current climate, however, such provisions look more poisonous than ever.
Some species, including the popular flathead catfish, aren't poisonous at all.
Snake loads up on noxious predator repellant by consuming poisonous toads.
Arizonans get into more trouble with poisonous creatures than do the residents of any other state.
All parts of plant, especially bulbs, are poisonous if ingested.
Some sea snails produce poisonous darts to hunt small fish and defend themselves.
The fins of these prickly fish carry poisonous venom.
Scientists have discovered a long-armed octopus that mimics poisonous creatures of the sea to avoid its predators.

British Dictionary definitions for poisonous

poisonous

/ˈpɔɪzənəs/

adjective

having the effects or qualities of a poison

capable of killing or inflicting injury; venomous

corruptive or malicious

Derived Forms

poisonously, adverb
poisonousness, noun

Word Origin and History for poisonous

adj.

1570s, from poison (n.) + -ous. Failed 16c. rivals were poisonsome, poisonful, poisony. Earlier poisoned was used (late 15c.). Related: Poisonously; poisonousness.

poisonous in Medicine

poisonous poi·son·ous (poi'zə-nəs)
adj.
Relating to or caused by a poison.