The Collaborative International Dictionary of English v.0.48:

Pretorian \Pre*to"ri*an\, n.
   A soldier of the pretorian guard.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Pretorian \Pre*to"ri*an\, a. [L. praetorians: cf. F.
   pr['e]torien.]
   Of or pertaining to a pretor or magistrate; judicial;
   exercised by, or belonging to, a pretor; as, pretorian power
   or authority.
   [1913 Webster]

   Pretorian bands or Pretorian guards, or Pretorians
      (Rom. Hist.), the emperor's bodyguards, instituted by the
      Emperor Augustus in nine cohorts of 1,000 men each.

   Pretorian gate (Rom. Antiq.), that one of the four gates in
      a camp which lay next the enemy. --Brande & C.
      [1913 Webster]

WordNet (r) 3.0 (2006):

pretorian
    adj 1: of or relating to a Roman praetor; "praetorial powers"
           [syn: praetorian, praetorial, pretorian,
           pretorial]
    2: characteristic of or similar to the corruptible soldiers in
       the Praetorian Guard with respect to corruption or political
       venality; "a large Praetorian bureaucracy filled with
       ambitious...and often sycophantic people makes work and makes
       trouble"- Arthur M.Schlesinger Jr. [syn: Praetorian,
       Pretorian]