poisonous

Universal Words adjective 1 causing death or illness if swallowed or absorbed into the body SYNTOXIC: poisonous chemicals / plants * This gas is highly poisonous. * The leaves of certain trees are poisonous to cattle. 2 (of animals and insects) producing a poison that can cause death or illness if the animal or insect bites you SYNVENOMOUS: poisonous snakes * a tiny spider with a poisonous bite 3 extremely unpleasant or unfriendly: a poisonous person * the poisonous atmosphere in the office