The Collaborative International Dictionary of English v.0.48:

Regulate \Reg"u*late\ (-l[=a]t), v. t. [imp. & p. p. Regulated
   (-l[=a]`t[e^]d); p. pr. & vb. n. Regulating.] [L.
   regulatus, p. p. of regulare, fr. regula. See Regular.]
   1. To adjust by rule, method, or established mode; to direct
      by rule or restriction; to subject to governing principles
      or laws.
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            The laws which regulate the successions of the
            seasons. --Macaulay.
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            The herdsmen near the frontier adjudicated their own
            disputes, and regulated their own police.
                                                  --Bancroft.
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   2. To put in good order; as, to regulate the disordered state
      of a nation or its finances.
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   3. To adjust, or maintain, with respect to a desired rate,
      degree, or condition; as, to regulate the temperature of a
      room, the pressure of steam, the speed of a machine, etc.
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   To regulate a watch or To regulate a clock, to adjust its
      rate of running so that it will keep approximately
      standard time.
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   Syn: To adjust; dispose; methodize; arrange; direct; order;
        rule; govern.
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WordNet (r) 3.0 (2006):

regulate
    v 1: fix or adjust the time, amount, degree, or rate of;
         "regulate the temperature"; "modulate the pitch" [syn:
         regulate, modulate]
    2: bring into conformity with rules or principles or usage;
       impose regulations; "We cannot regulate the way people
       dress"; "This town likes to regulate" [syn: regulate,
       regularize, regularise, order, govern] [ant:
       deregulate]
    3: shape or influence; give direction to; "experience often
       determines ability"; "mold public opinion" [syn: determine,
       shape, mold, influence, regulate]
    4: check the emission of (sound) [syn: baffle, regulate]