POISONOUS
poisonous, venomous, vicious
(adjective) marked by deep ill will; deliberately harmful; “poisonous hate”; “venomous criticism”; “vicious gossip”
poisonous
(adjective) not safe to eat
poisonous, toxicant
(adjective) having the qualities or effects of a poison
Source: WordNet® 3.1
Etymology
Adjective
poisonous (comparative more poisonous, superlative most poisonous)
Containing sufficient poison to be dangerous to touch or ingest.
Synonyms: poisoned, toxic, venomous, attery (dialectal or archaic)
Antonyms: nonpoisonous, unpoisonous
(figuratively) Negative, harmful.
Synonym: toxic
Usage notes
Some speakers make a distinction between poisonous (releasing toxins when eaten), and venomous (releasing toxins (known as venom in this case) by biting a target), especially in non-colloquial speech.
Source: Wiktionary
Poi"son*ous, a.
Definition: Having the qualities or effects of poison; venomous; baneful;
corrupting; noxious. Shak.
– Poi"son*ous*ly, adv.
– Poi"son*ous*ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition