The Collaborative International Dictionary of English v.0.48:

Typhoid \Ty"phoid\, a. [Typhus + -oid: cf. F. typho["i]de, Gr.
   ?. See Typhus.] (Med.)
   Of or pertaining to typhus; resembling typhus; of a low grade
   like typhus; as, typhoid symptoms.
   [1913 Webster]

   Typhoid fever, a disease formerly confounded with typhus,
      but essentially different from the latter. It is
      characterized by fever, lasting usually three or more
      weeks, diarrhaea with evacuations resembling pea soup in
      appearance, and prostration and muscular debility,
      gradually increasing and often becoming profound at the
      acme of the disease. Its local lesions are a scanty
      eruption of spots, resembling flea bites, on the belly,
      enlargement of the spleen, and ulceration of the
      intestines over the areas occupied by Peyer's glands. The
      virus, or contagion, of this fever is supposed to be a
      microscopic vegetable organism, or bacterium. Called also
      enteric fever. See Peyer's glands.

   Typhoid state, a condition common to many diseases,
      characterized by profound prostration and other symptoms
      resembling those of typhus.
      [1913 Webster]
      [1913 Webster]

WordNet (r) 3.0 (2006):

typhoid
    n 1: serious infection marked by intestinal inflammation and
         ulceration; caused by Salmonella typhosa ingested with food
         or water [syn: typhoid, typhoid fever, enteric fever]