The Collaborative International Dictionary of English v.0.48:

Empiric \Em*pir"ic\, Empirical \Em*pir"ic*al\, a.
   1. Pertaining to, or founded upon, experiment or experience;
      depending upon the observation of phenomena; versed in
      experiments.
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            In philosophical language, the term empirical means
            simply what belongs to or is the product of
            experience or observation.            --Sir W.
                                                  Hamilton.
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            The village carpenter . . . lays out his work by
            empirical rules learnt in his apprenticeship. --H.
                                                  Spencer.
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   2. Depending upon experience or observation alone, without
      due regard to science and theory; -- said especially of
      medical practice, remedies, etc.; wanting in science and
      deep insight; as, empiric skill, remedies.
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   Empirical formula. (Chem.) See under Formula.

   Syn: See Transcendental.
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WordNet (r) 3.0 (2006):

empirical
    adj 1: derived from experiment and observation rather than
           theory; "an empirical basis for an ethical theory";
           "empirical laws"; "empirical data"; "an empirical
           treatment of a disease about which little is known" [syn:
           empirical, empiric] [ant: theoretic, theoretical]
    2: relying on medical quackery; "empiric treatment" [syn:
       empiric, empirical]