The Collaborative International Dictionary of English v.0.48:

Structure \Struc"ture\, n. [L. structura, from struere,
   structum, to arrange, build, construct; perhaps akin to E.
   strew: cf. F. structure. Cf. Construe, Destroy,
   Instrument, Obstruct.]
   1. The act of building; the practice of erecting buildings;
      construction. [R.]
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            His son builds on, and never is content
            Till the last farthing is in structure spent. --J.
                                                  Dryden, Jr.
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   2. Manner of building; form; make; construction.
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            Want of insight into the structure and constitution
            of the terraqueous globe.             --Woodward.
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   3. Arrangement of parts, of organs, or of constituent
      particles, in a substance or body; as, the structure of a
      rock or a mineral; the structure of a sentence.
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            It [basalt] has often a prismatic structure. --Dana.
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   4. (Biol.) Manner of organization; the arrangement of the
      different tissues or parts of animal and vegetable
      organisms; as, organic structure, or the structure of
      animals and plants; cellular structure.
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   5. That which is built; a building; esp., a building of some
      size or magnificence; an edifice.
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            There stands a structure of majestic frame. --Pope.
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   Columnar structure. See under Columnar.
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WordNet (r) 3.0 (2006):

structure
    n 1: a thing constructed; a complex entity constructed of many
         parts; "the structure consisted of a series of arches";
         "she wore her hair in an amazing construction of whirls and
         ribbons" [syn: structure, construction]
    2: the manner of construction of something and the arrangement
       of its parts; "artists must study the structure of the human
       body"; "the structure of the benzene molecule"
    3: the complex composition of knowledge as elements and their
       combinations; "his lectures have no structure"
    4: a particular complex anatomical part of a living thing; "he
       has good bone structure" [syn: structure, anatomical
       structure, complex body part, bodily structure, body
       structure]
    5: the people in a society considered as a system organized by a
       characteristic pattern of relationships; "the social
       organization of England and America is very different";
       "sociologists have studied the changing structure of the
       family" [syn: social organization, social organisation,
       social structure, social system, structure]
    v 1: give a structure to; "I need to structure my days"