The Collaborative International Dictionary of English v.0.48:

Decide \De*cide"\, v. t. [imp. & p. p. Decided; p. pr. & vb.
   n. Deciding.] [L. dec[imac]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.]
      [1913 Webster]

            Our seat denies us traffic here;
            The sea, too near, decides us from the rest.
                                                  --Fuller.
      [1913 Webster]

   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.
      [1913 Webster]

            So shall thy judgment be; thyself hast decided it.
                                                  --1 Kings xx.
                                                  40.
      [1913 Webster]

            The quarrel toucheth none but us alone;
            Betwixt ourselves let us decide it then. --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]

         Who shall decide, when doctors disagree? --Pope.
   [1913 Webster]

WordNet (r) 3.0 (2006):

decide
    v 1: reach, make, or come to a decision about something; "We
         finally decided after lengthy deliberations" [syn:
         decide, 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: decide, 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"

Moby Thesaurus II by Grady Ward, 1.0:

95 Moby Thesaurus words for "decide":
   adjudge, adjudicate, advance, arbitrate, ascertain, assure, bring,
   call the shots, carry, certify, choose, choose to, cinch, clear up,
   clinch, command, conclude, conduce to, conjecture, contribute to,
   control, decide upon, decree, desire, determine, direct,
   dismiss all doubt, dispose, elect, engage, enlist, ensure,
   establish, figure, find, find out, fix, forward, gather, get at,
   get to do, govern, guess, guide, incline, induce, influence,
   insure, interest in, judge, lead, lead to, lure, make a decision,
   make certain, make no doubt, make no mistake, make sure,
   make sure of, nail down, opt for, order, pick out, procure, prompt,
   purpose, reassure, redound to, referee, regulate, remove all doubt,
   resolve, rule, seal, see fit, see that, see to it, select, set,
   set at rest, settle, sort out, subserve, surmise, sway,
   take a resolution, tempt, think fit, think good, think proper,
   turn the scale, umpire, wear the pants, will, wish



The Devil's Dictionary (1881-1906):

DECIDE, v.i.  To succumb to the preponderance of one set of influences
over another set.

    A leaf was riven from a tree,
    "I mean to fall to earth," said he.

    The west wind, rising, made him veer.
    "Eastward," said he, "I now shall steer."

    The east wind rose with greater force.
    Said he:  "'Twere wise to change my course."

    With equal power they contend.
    He said:  "My judgment I suspend."

    Down died the winds; the leaf, elate,
    Cried:  "I've decided to fall straight."

    "First thoughts are best?"  That's not the moral;
    Just choose your own and we'll not quarrel.

    Howe'er your choice may chance to fall,
    You'll have no hand in it at all.
                                                                  G.J.