The Collaborative International Dictionary of English v.0.48:

Praetorium \Pr[ae]*to"ri*um\, n.
   See Pretorium.
   [1913 Webster]

WordNet (r) 3.0 (2006):

praetorium
    n 1: the tent of an ancient Roman general [syn: praetorium,
         pretorium]

Easton's 1897 Bible Dictionary:

Praetorium
   The Greek word (praitorion) thus rendered in Mark 15:16 is
   rendered "common hall" (Matt. 27:27, marg., "governor's house"),
   "judgment hall," (John 18:28, 33, marg., "Pilate's house", 19:9;
   Acts 23:35), "palace" (Phil. 1:13). This is properly a military
   word. It denotes (1) the general's tent or headquarters; (2) the
   governor's residence, as in Acts 23:35 (R.V., "palace"); and (3)
   the praetorian guard (See PALACE), or the camp or
   quarters of the praetorian cohorts (Acts 28:16), the imperial
   guards in immediate attendance on the emperor, who was "praetor"
   or commander-in-chief.