The Collaborative International Dictionary of English v.0.48:

Capitulate \Ca*pit"u*late\, v. i. [imp. & p. p. Capitulated;
   p. pr. & vb. n. Capitulating.] [LL. capitulatus, p. p. of
   capitulare to capitulate: cf. F. capituler. See Capitular,
   n.]
   1. To settle or draw up the heads or terms of an agreement,
      as in chapters or articles; to agree. [Obs.]
      [1913 Webster]

            There capitulates with the king . . . to take to
            wife his daughter Mary.               --Heylin.
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            There is no reason why the reducing of any agreement
            to certain heads or capitula should not be called to
            capitulate.                           --Trench.
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   2. To surrender on terms agreed upon (usually, drawn up under
      several heads); as, an army or a garrison capitulates.
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            The Irish, after holding out a week, capitulated.
                                                  --Macaulay.
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The Collaborative International Dictionary of English v.0.48:

Capitulate \Ca*pit"u*late\, v. t.
   To surrender or transfer, as an army or a fortress, on
   certain conditions. [R.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

capitulate
    v 1: surrender under agreed conditions

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "capitulate":
   abandon, acknowledge defeat, acquiesce, beg a truce, bow, cave,
   cede, come to terms, concede, cry pax, cry quits, defer, give in,
   give over, give up, implore mercy, knuckle, knuckle under,
   pray for quarter, relent, relinquish, renounce, say uncle, submit,
   succumb, surrender, yield, yield the palm