Source : Webster's Revised Unabridged Dictionary (1913)

Venomous \Ven"om*ous\, a. [OE. venemous, venimous, F. venimeux,
   L. venenosus, fr. venenum poison. See {Venom}, and cf.
   {Venenose}.]
   1. Full of venom; noxious to animal life; poisonous; as, the
      bite of a serpent may be venomous.

   2. (Zo["o]l.) Having a poison gland or glands for the
      secretion of venom, as certain serpents and insects.

   3. Noxious; mischievous; malignant; spiteful; as, a venomous
      progeny; a venomous writer.

   {Venomous snake} (Zo["o]l.), any serpent which has poison
      glands and fangs, whether dangerous to man or not. These
      serpents constitute two tribes, the viperine serpents, or
      Solenoglypha, and the cobralike serpents, or
      Proteroglypha. The former have perforated, erectile fangs
      situated in the front part of the upper jaw, and are
      without ordinary teeth behind the fangs; the latter have
      permanently erect and grooved fangs, with ordinary
      maxillary teeth behind them. -- {Ven"om*ous*ly}, adv. --
      {Ven"om*ous*ness}, n.

Source : WordNet®

venomous
     adj 1: extremely poisonous or injurious; producing venom; "venomous
            snakes"; "a virulent insect bite" [syn: {deadly}, {virulent}]
     2: harsh or corrosive in tone; "an acerbic tone piercing
        otherwise flowery prose"; "a barrage of acid comments";
        "her acrid remarks make her many enemies"; "bitter words";
        "blistering criticism"; "caustic jokes about political
        assassination, talk-show hosts and medical ethics"; "a
        sulfurous denunciation" [syn: {acerb}, {acerbic}, {acid},
        {acrid}, {bitter}, {blistering}, {caustic}, {sulfurous}, {sulphurous},
         {virulent}, {vitriolic}]
     3: marked by deep ill will; deliberately harmful; "a malevolent
        lie"; "poisonous hate...in his eyes"- Ernest Hemingway;
        "venomous criticism"; "vicious gossip" [syn: {poisonous},
        {vicious}]