The Collaborative International Dictionary of English v.0.48:

Theist \The"ist\, n. [Cf. F. th['e]iste. See Theism.]
   One who believes in the existence of a God; especially, one
   who believes in a personal God; -- opposed to atheist.
   [1913 Webster] Theistic

The Collaborative International Dictionary of English v.0.48:

Deist \De"ist\ (d[=e]"[i^]st), n. [L. deus god: cf. F.
   d['e]iste. See Deity.]
   One who believes in the existence of a God, but denies
   revealed religion; a freethinker.
   [1913 Webster]

   Note: A deist, as denying a revelation, is opposed to a
         Christian; as, opposed to the denier of a God, whether
         atheist or pantheist, a deist is generally
         denominated theist. --Latham.

   Syn: See Infidel. Deistic

WordNet (r) 3.0 (2006):

theist
    adj 1: of or relating to theism [syn: theist, theistical,
           theistic]
    n 1: one who believes in the existence of a god or gods