POISONOUS

adj. 1 lethal, deadly, fatal, mortal, toxic, septic, virulent, noxious or rare nocuous, venomous, malignant, pernicious, miasmic, mephitic Poisonous effluents were leaked into the rivers by the chemical plant 2 malicious, malevolent, malignant, corruptive, vicious, baleful, evil, foul, diabolic(al), defamatory, libellous, slanderous, dangerous, deleterious, They have been spreading poisonous gossip about him again