The Collaborative International Dictionary of English v.0.48:

Concern \Con*cern"\, v. t. [imp. & p. p. Concerned; p. pr. &
   vb. n. Concerning.] [F. concerner, LL. concernere to
   regard, concern, fr. L. concernere to mix or mingle together,
   as in a sieve for separating; con- + cernere to separate,
   sift, distinguish by the senses, and especially by the eyes,
   to perceive, see. See Certain.]
   1. To relate or belong to; to have reference to or connection
      with; to affect the interest of; to be of importance to.
      [1913 Webster]

            Preaching the kingdom of God, and teaching those
            things which concern the Lord Jesus Christ. --Acts
                                                  xxviii. 31.
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            Our wars with France have affected us in our most
            tender interests, and concerned us more than those
            with any other nation.                --Addison.
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            It much concerns a preacher first to learn
            The genius of his audience and their turn.
                                                  --Dodsley.
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            Ignorant, so far as the usual instruction is
            concerned.                            --J. F.
                                                  Cooper.
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   2. To engage by feeling or sentiment; to interest; as, a good
      prince concerns himself in the happiness of his subjects.
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            They think themselves out the reach of Providence,
            and no longer concerned to solicit his favor.
                                                  --Rogers.
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The Collaborative International Dictionary of English v.0.48:

Concerned \Con*cerned"\, a. [See Concern, v. t., 2.]
   Disturbed; troubled; solicitous; as, to be much concerned for
   the safety of a friend.
   [1913 Webster]

WordNet (r) 3.0 (2006):

concerned
    adj 1: feeling or showing worry or solicitude; "concerned
           parents of youthful offenders"; "was concerned about the
           future"; "we feel concerned about accomplishing the task
           at hand"; "greatly concerned not to disappoint a small
           child" [ant: unconcerned]
    2: involved in or affected by or having a claim to or share in;
       "a memorandum to those concerned"; "an enterprise in which
       three men are concerned"; "factors concerned in the rise and
       fall of epidemics"; "the interested parties met to discuss
       the business" [syn: concerned, interested]
    3: culpably involved; "all those concerned in the bribery case
       have been identified"; "named three officials implicated in
       the plot"; "an innocent person implicated by circumstances in
       a crime" [syn: implicated, concerned]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "concerned":
   a party to, active, affected, agitated, all-overish, anxious,
   anxioused up, apprehensive, attracted, bothered, caring, cathectic,
   curious, disquieted, distressed, disturbed, enthusiastic, excited,
   fascinated, fearful, foreboding, implicated, in a pucker,
   in a stew, included, interested, involved, keen on, misgiving,
   nervous, on tenterhooks, overanxious, overapprehensive, passionate,
   perturbed, piqued, responsible, solicitous, strained, suspenseful,
   tantalized, tense, tickled, titillated, troubled, turned-on,
   uneasy, upset, vexed, worried, zealous