The Collaborative International Dictionary of English v.0.48:

Rex \Rex\, n.; pl. Reges. [L.]
   A king.
   [1913 Webster]

   To play rex, to play the king; to domineer. [Obs.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

Rex
    n 1: a male sovereign; ruler of a kingdom [syn: king, male
         monarch, Rex] [ant: female monarch, queen, queen
         regnant]

The Free On-line Dictionary of Computing (30 December 2018):

REX

   The original name for Restructured EXtended eXecutor.


U.S. Gazetteer Places (2000):

Rex, NC -- U.S. Census Designated Place in North Carolina
   Population (2000):    55
   Housing Units (2000): 17
   Land area (2000):     0.736317 sq. miles (1.907053 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.736317 sq. miles (1.907053 sq. km)
   FIPS code:            56100
   Located within:       North Carolina (NC), FIPS 37
   Location:             34.848018 N, 79.042034 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Rex, NC
    Rex