The Collaborative International Dictionary of English v.0.48:

Subordination \Sub*or`di*na"tion\, n. [Cf. F. subordination.]
   1. The act of subordinating, placing in a lower order, or
      subjecting.
      [1913 Webster]

   2. The quality or state of being subordinate or inferior to
      an other; inferiority of rank or dignity; subjection.
      [1913 Webster]

            Natural creature having a local subordination.
                                                  --Holyday.
      [1913 Webster]

   3. Place of inferior rank.
      [1913 Webster]

            Persons who in their several subordinations would be
            obliged to follow the example of their superiors.
                                                  --Swift.
      [1913 Webster]

WordNet (r) 3.0 (2006):

subordination
    n 1: the state of being subordinate to something
    2: the semantic relation of being subordinate or belonging to a
       lower rank or class [syn: hyponymy, subordination]
    3: the grammatical relation of a modifying word or phrase to its
       head
    4: the quality of obedient submissiveness [ant:
       insubordination]
    5: the act of mastering or subordinating someone [syn:
       mastery, subordination]