The Collaborative International Dictionary of English v.0.48:

Tract \Tract\, n. [Abbrev.fr. tractate.]
   A written discourse or dissertation, generally of short
   extent; a short treatise, especially on practical religion.
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         The church clergy at that time writ the best collection
         of tracts against popery that ever appeared. --Swift.
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   Tracts for the Times. See Tractarian.
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The Collaborative International Dictionary of English v.0.48:

Tract \Tract\, n. [L. tractus a drawing, train, track, course,
   tract of land, from trahere tractum, to draw. Senses 4 and 5
   are perhaps due to confusion with track. See Trace,v., and
   cf. Tratt.]
   1. Something drawn out or extended; expanse. "The deep tract
      of hell." --Milton.
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   2. A region or quantity of land or water, of indefinite
      extent; an area; as, an unexplored tract of sea.
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            A very high mountain joined to the mainland by a
            narrow tract of earth.                --Addison.
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   3. Traits; features; lineaments. [Obs.]
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            The discovery of a man's self by the tracts of his
            countenance is a great weakness.      --Bacon.
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   4. The footprint of a wild beast. [Obs.] --Dryden.
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   5. Track; trace. [Obs.]
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            Efface all tract of its traduction.   --Sir T.
                                                  Browne.
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            But flies an eagle flight, bold, and forthon,
            Leaving no tract behind.              --Shak.
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   6. Treatment; exposition. [Obs.] --Shak.
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   7. Continuity or extension of anything; as, the tract of
      speech. [Obs.] --Older.
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   8. Continued or protracted duration; length; extent.
      "Improved by tract of time." --Milton.
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   9. (R. C. Ch.) Verses of Scripture sung at Mass, instead of
      the Alleluia, from Septuagesima Sunday till the Saturday
      befor Easter; -- so called because sung tractim, or
      without a break, by one voice, instead of by many as in
      the antiphons.
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   Syn: Region; district; quarter; essay; treatise;
        dissertation.
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The Collaborative International Dictionary of English v.0.48:

Tract \Tract\, v. t.
   To trace out; to track; also, to draw out; to protact. [Obs.]
   --Spenser. --B. Jonson.
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WordNet (r) 3.0 (2006):

tract
    n 1: an extended area of land [syn: tract, piece of land,
         piece of ground, parcel of land, parcel]
    2: a system of body parts that together serve some particular
       purpose
    3: a brief treatise on a subject of interest; published in the
       form of a booklet [syn: tract, pamphlet]
    4: a bundle of myelinated nerve fibers following a path through
       the brain [syn: nerve pathway, tract, nerve tract,
       pathway]

Moby Thesaurus II by Grady Ward, 1.0:

139 Moby Thesaurus words for "tract":
   acreage, amplitude, area, article, assembly-line housing, belt,
   billeting, block, booklet, breadth, brochure, causerie, chapbook,
   circular, clearing, clos, close, comic book, continuum, corn field,
   critique, croft, cultivated land, descant, dimension, discourse,
   discussion, disquisition, dissertation, district, domiciliation,
   doss, emptiness, empty space, enclave, essay, etude, examination,
   excursus, expanse, expansion, exposition, extension, extent,
   feature, field, first approach, folder, footstep, forty,
   galactic space, hayfield, homily, hospitality, housing,
   housing bill, housing development, housing problem, infinite space,
   interstellar space, introductory study, kraal, leaflet,
   living quarters, lodging, lodgment, lot, lower-income housing,
   lucubration, measure, memoir, monograph, morceau, note,
   nothingness, outer space, outline, paddy, pale, pamphlet, pandect,
   paper, paragraph, parcel, parcel of land, part, patch, piece,
   piece of land, plat, plot, plot of ground, portion,
   preliminary study, prolegomenon, proportion, quad, quadrangle,
   quarter, quartering, real estate, region, research paper,
   rice paddy, screed, section, sector, sermon, sketch,
   slum clearance, space, spatial extension, special article, sphere,
   spoor, spread, square, step, stretch, study, subdivision,
   superficial extension, surface, survey, term paper, territory,
   theme, thesis, track, tractate, transient lodging, treatise,
   treatment, urban renewal, vestige, void, volume, wheat field,
   zone