Source : Webster's Revised Unabridged Dictionary (1913)

Decide \De*cide"\, v. t. [imp. & p. p. {Decided}; p. pr. & vb.
   n. {Deciding}.] [L. dec[=i]dere; de- + caedere to cut, cut
   off; prob. akin to E. shed, v.: cf. F. d['e]cider. Cf.
   {Decision}.]
   1. To cut off; to separate. [Obs.]

            Our seat denies us traffic here; The sea, too near,
            decides us from the rest.             --Fuller.

   2. To bring to a termination, as a question, controversy,
      struggle, by giving the victory to one side or party; to
      render judgment concerning; to determine; to settle.

            So shall thy judgment be; thyself hast decided it.
                                                  --1 Kings xx.
                                                  40.

            The quarrel toucheth none but us alone; Betwixt
            ourselves let us decide it then.      --Shak.

Decide \De*cide"\, v. i.
   To determine; to form a definite opinion; to come to a
   conclusion; to give decision; as, the court decided in favor
   of the defendant.

         Who shall decide, when doctors disagree? --Pope.

Source : WordNet®

decide
     v 1: reach, make, or come to a decision about something; "We
          finally decided after lengthy deliberations" [syn: {make
          up one's mind}, {determine}]
     2: bring to an end; settle conclusively; "The case was
        decided"; "The judge decided the case in favor of the
        plaintiff"; "The father adjudicated when the sons were
        quarreling over their inheritance" [syn: {settle}, {resolve},
         {adjudicate}]
     3: cause to decide; "This new development finally decided me!"
     4: influence or determine; "The vote in New Hampshire often
        decides the outcome of the Presidential election"