The Collaborative International Dictionary of English v.0.48:

Nauseous \Nau"seous\ (?; 277), a. [L. nauseosus.]
   1. Causing, or fitted to cause, nausea; sickening; loathsome;
      disgusting; exciting abhorrence; as, a nauseous drug or
      medicine.
      [1913 Webster]

   2. Feeling nausea; as, nauseous from the effects of
      chemotherapy.
      [PJC] -- Nau"seous*ly, adv. -- Nau"seous*ness, n.
      [1913 Webster]

            The nauseousness of such company disgusts a
            reasonable man.                       --Dryden.
      [1913 Webster]