Source : Webster's Revised Unabridged Dictionary (1913)

Pestiferous \Pes*tif"er*ous\, a. [L. pestiferus, pestifer;
   pestis pest + ferre to bear: cf. F. pestif[`e]re.]
   1. Pest-bearing; pestilential; noxious to health; malignant;
      infectious; contagious; as, pestiferous bodies. ``Poor,
      pestiferous creatures begging alms.'' --Evelyn.
      ``Unwholesome and pestiferous occupations.'' --Burke.

   2. Noxious to peace, to morals, or to society; vicious;
      hurtful; destructive; as, a pestiferous demagogue.

            Pestiferous reports of men very nobly held. --Shak.

Source : WordNet®

pestiferous
     adj 1: contaminated with infecting organisms; "dirty wounds";
            "obliged to go into infected rooms"- Jane Austen [syn:
             {contaminated}, {dirty}, {infected}]
     2: likely to spread and cause an epidemic disease; "a
        pestilential malignancy in the air"- Jonathan Swift;
        "plaguey fevers" [syn: {pestilent}, {pestilential}, {plaguey}]
     3: tending to corrupt or pervert [syn: {corruptive}, {perversive}]
     4: causing irritation or annoyance; "tapping an annoying rhythm
        on his glass with his fork"; "aircraft noise is
        particularly bothersome near the airport"; "found it
        galling to have to ask permission"; "an irritating delay";
        "nettlesome paperwork"; "a pesky mosquito"; "swarms of
        pestering gnats"; "a plaguey newfangled safety catch"; "a
        teasing and persistent thought annoyed him"; "a vexatious
        child"; "it is vexing to have to admit you are wrong"
        [syn: {annoying}, {bothersome}, {galling}, {irritating}, {nettlesome},
         {pesky}, {pestering}, {plaguy}, {plaguey}, {teasing}, {vexatious},
         {vexing}]