The Collaborative International Dictionary of English v.0.48:

Synchronize \Syn"chro*nize\, v. i. [imp. & p. p. Synchronized;
   p. pr. & vb. n. Synchronizing.] [Gr. ?.]
   To agree in time; to be simultaneous.
   [1913 Webster]

         The path of this great empire, through its arch of
         progress, synchronized with that of Christianity. --De
                                                  Quincey.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Synchronize \Syn"chro*nize\, v. t.
   1. To assign to the same date or period of time; as, to
      synchronize two events of Greek and Roman history.
      "Josephus synchronizes Nisan with the Egyptian Pharmus."
      --W. L. Bevan.
      [1913 Webster]

   2. To cause to agree in time; as, to synchronize the
      movements of different machines; to synchronize clocks.
      [1913 Webster]

WordNet (r) 3.0 (2006):

synchronize
    v 1: make synchronous and adjust in time or manner; "Let's
         synchronize our efforts" [syn: synchronize,
         synchronise, sync] [ant: desynchronise,
         desynchronize]
    2: happen at the same time [syn: synchronize, synchronise,
       contemporize, contemporise]
    3: make (motion picture sound) exactly simultaneous with the
       action; "synchronize this film" [syn: synchronize,
       synchronise]
    4: arrange or represent events so that they co-occur;
       "synchronize biblical events" [syn: synchronize,
       synchronise, contemporize, contemporise]
    5: operate simultaneously; "The clocks synchronize" [syn:
       synchronize, synchronise]
    6: cause to indicate the same time or rate; "synchronize your
       watches" [syn: synchronize, synchronise]

Moby Thesaurus II by Grady Ward, 1.0:

90 Moby Thesaurus words for "synchronize":
   accommodate, accompany, accord, adapt, adjust, adjust to, agree,
   assimilate, associate, assonate, atone, attune, be harmonious,
   be in cahoots, be in phase, be in time, be in tune, blend, chart,
   chime, chord, coact, coadunate, codify, coexist, coextend,
   coincide, collaborate, collude, combine, concur, conjoin, connive,
   conspire, contemporize, cooperate, coordinate, correspond, cut to,
   equalize, fit, fix, gear to, happen together, harmonize,
   homologate, homologize, isochronize, join, keep in step,
   keep pace with, key to, make plumb, make uniform, match, measure,
   melodize, methodize, musicalize, normalize, organize, plan,
   proportion, put in tune, rationalize, reconcile, rectify,
   regularize, regulate, right, routinize, set, set right, settle,
   similarize, sound in tune, sound together, standardize, symphonize,
   sync, synergize, systematize, tailor, time, trim to, true, true up,
   tune, tune up, unite