Source : Webster's Revised Unabridged Dictionary (1913)

Concert \Con*cert"\, v. t. [imp. & p. p. {Concerted}; p. pr. &
   vb. n. {Concerting}.] [F. concerter, It. concertare,
   conertare, prob. from L. consertus, p. p. of conserere to
   join together; con- + serere to join together, influenced by
   concertare to contend; con- + centare to strive; properly, to
   try to decide; fr. cernere to distinguish. See {Series}, and
   cf. {Concern}.]
   1. To plan together; to settle or adjust by conference,
      agreement, or consultation.

            It was concerted to begin the siege in March. --Bp.
                                                  Burnet.

   2. To plan; to devise; to arrange.

            A commander had more trouble to concert his defense
            before the people than to plan . . . the campaign.
                                                  --Burke.