The Collaborative International Dictionary of English v.0.48:

Organize \Or"gan*ize\ ([^o]r"gan*[imac]z), v. t. [imp. & p. p.
   Organized ([^o]r"gan*[imac]zd); p. pr. & vb. n.
   Organizing ([^o]r"gan*[imac]*z[i^]ng).] [Cf. F. organiser,
   Gr. 'organi`zein. See Organ.]
   1. (Biol.) To furnish with organs; to give an organic
      structure to; to endow with capacity for the functions of
      life; as, an organized being; organized matter; -- in this
      sense used chiefly in the past participle.
      [1913 Webster]

            These nobler faculties of the mind, matter organized
            could never produce.                  --Ray.
      [1913 Webster]

   2. To arrange or constitute in parts, each having a special
      function, act, office, or relation; to systematize; to get
      into working order; -- applied to products of the human
      intellect, or to human institutions and undertakings, as a
      science, a government, an army, a war, etc.
      [1913 Webster]

            This original and supreme will organizes the
            government.                           --Cranch.
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   3. (Mus.) To sing in parts; as, to organize an anthem. [R.]
      --Busby.
      [1913 Webster]

WordNet (r) 3.0 (2006):

organize
    v 1: create (as an entity); "social groups form everywhere";
         "They formed a company" [syn: form, organize,
         organise]
    2: cause to be structured or ordered or operating according to
       some principle or idea [syn: organize, organise] [ant:
       disorganise, disorganize]
    3: plan and direct (a complex undertaking); "he masterminded the
       robbery" [syn: mastermind, engineer, direct,
       organize, organise, orchestrate]
    4: bring order and organization to; "Can you help me organize my
       files?" [syn: organize, organise, coordinate]
    5: arrange by systematic planning and united effort; "machinate
       a plot"; "organize a strike"; "devise a plan to take over the
       director's office" [syn: organize, organise, prepare,
       devise, get up, machinate]
    6: form or join a union; "The auto workers decided to unionize"
       [syn: unionize, unionise, organize, organise]