The Collaborative International Dictionary of English v.0.48:

Control \Con*trol"\, v. t. [imp. & p. p. Controlled; p. pr. &
   vb. n. Controlling.] [F. contr[^o]ler, fr. contr[^o]le.]
   [Formerly written comptrol and controul.]
   1. To check by a counter register or duplicate account; to
      prove by counter statements; to confute. [Obs.]
      [1913 Webster]

            This report was controlled to be false. --Fuller.
      [1913 Webster]

   2. To exercise restraining or governing influence over; to
      check; to counteract; to restrain; to regulate; to govern;
      to overpower.
      [1913 Webster]

            Give me a staff of honor for mine age,
            But not a scepter to control the world. --Shak.
      [1913 Webster]

            I feel my virtue struggling in my soul:
            But stronger passion does its power control.
                                                  --Dryden.

   3. to assure the validity of an experimental procedure by
      using a control[7].
      [PJC]

   Syn: To restrain; rule; govern; manage; guide; regulate;
        hinder; direct; check; curb; counteract; subdue.
        [1913 Webster]

WordNet (r) 3.0 (2006):

controlling
    adj 1: able to control or determine policy; "a controlling
           interest in the firm"

Moby Thesaurus II by Grady Ward, 1.0:

87 Moby Thesaurus words for "controlling":
   absolute, all-absorbing, ascendant, at the head, authoritarian,
   authoritative, authorized, autocratic, boss, capital, cardinal,
   chief, clothed with authority, commanding, competent,
   consequential, considerable, directing, directive, directorial,
   directory, dominant, duly constituted, eminent, empowered,
   ex officio, foremost, general, governing, great, guiding, head,
   hegemonic, hegemonistic, highest, imperative, important,
   in ascendancy, in charge, in chief, in the ascendant, influential,
   leading, main, managerial, managing, master, mighty, momentous,
   monocratic, official, overriding, overruling, paramount, potent,
   powerful, predominant, predominate, preeminent, premier,
   prepollent, preponderant, preponderate, prepotent, prestigious,
   prevalent, primary, prime, principal, prominent, puissant, ranking,
   regnant, regulating, regulative, regulatory, reigning, ruling,
   senior, sovereign, substantial, superior, supreme, topmost,
   totalitarian, uppermost, weighty