The Collaborative International Dictionary of English v.0.48:

Typhus \Ty"phus\, n. [NL., fr. Gr. ? smoke, cloud, stupor
   arising from fever; akin to ? to smoke, Skr. dh?pa smoke.]
   (Med.)
   A contagious continued fever lasting from two to three weeks,
   attended with great prostration and cerebral disorder, and
   marked by a copious eruption of red spots upon the body. Also
   called jail fever, famine fever, putrid fever,
   spottled fever, etc. See Jail fever, under Jail.
   [1913 Webster]

WordNet (r) 3.0 (2006):

typhus
    n 1: rickettsial disease transmitted by body lice and
         characterized by skin rash and high fever [syn: typhus,
         typhus fever]