The Collaborative International Dictionary of English v.0.48:

Essay \Es*say"\, v. t. [imp. & p. p. Essayed; p. pr. & vb. n.
   Essaying.] [F. essayer. See Essay, n.]
   1. To exert one's power or faculties upon; to make an effort
      to perform; to attempt; to endeavor; to make experiment or
      trial of; to try.
      [1913 Webster]

            What marvel if I thus essay to sing?  --Byron.
      [1913 Webster]

            Essaying nothing she can not perform. --Emerson.
      [1913 Webster]

            A danger lest the young enthusiast . . . should
            essay the impossible.                 --J. C.
                                                  Shairp.
      [1913 Webster]

   2. To test the value and purity of (metals); to assay. See
      Assay. [Obs.] --Locke.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Essay \Es"say\, n.; pl. Essays. [F. essai, fr. L. exagium a
   weighing, weight, balance; ex out + agere to drive, do; cf.
   examen, exagmen, a means of weighing, a weighing, the tongue
   of a balance, exigere to drive out, examine, weigh, Gr.
   'exa`gion a weight, 'exagia`zein to examine, 'exa`gein to
   drive out, export. See Agent, and cf. Exact, Examine,
   Assay.]
   1. An effort made, or exertion of body or mind, for the
      performance of anything; a trial; attempt; as, to make an
      essay to benefit a friend. "The essay at organization."
      --M. Arnold.
      [1913 Webster]

   2. (Lit.) A composition treating of any particular subject;
      -- usually shorter and less methodical than a formal,
      finished treatise; as, an essay on the life and writings
      of Homer; an essay on fossils, or on commerce.
      [1913 Webster]

   3. An assay. See Assay, n. [Obs.]

   Syn: Attempt; trial; endeavor; effort; tract; treatise;
        dissertation; disquisition.
        [1913 Webster]

WordNet (r) 3.0 (2006):

essay
    n 1: an analytic or interpretive literary composition
    2: a tentative attempt
    v 1: make an effort or attempt; "He tried to shake off his
         fears"; "The infant had essayed a few wobbly steps"; "The
         police attempted to stop the thief"; "He sought to improve
         himself"; "She always seeks to do good in the world" [syn:
         try, seek, attempt, essay, assay]
    2: put to the test, as for its quality, or give experimental use
       to; "This approach has been tried with good results"; "Test
       this recipe" [syn: test, prove, try, try out,
       examine, essay]

Moby Thesaurus II by Grady Ward, 1.0:

176 Moby Thesaurus words for "essay":
   acid test, approach, article, assay, attempt, autograph, bid,
   blank determination, brainchild, bring to test, brouillon,
   causerie, chance, composition, computer printout, confirm, copy,
   crack, criterion, crucial test, crucible, cut and try, descant,
   determination, discourse, discussion, disquisition, dissertation,
   docimasy, document, draft, edited version, effort, endeavor,
   engage, engrossment, etude, examination, excursus, exertion,
   experiment, explication, exposition, fair copy, feature,
   feeling out, fiction, final draft, finished version,
   first approach, first draft, flimsy, fling, gambit, give a try,
   give a tryout, go, go about, hassle, have a go, holograph, homily,
   introductory study, kiteflying, labor, letter, lick, lift a finger,
   literae scriptae, literary artefact, literary production,
   literature, lucubration, make an attempt, make an effort,
   manuscript, matter, memoir, monograph, morceau, move, nonfiction,
   note, offer, opus, ordeal, original, outline, pandect, paper,
   paragraph, parchment, penscript, piece, piece of writing, play,
   play around with, poem, practice upon, preliminary study,
   printed matter, printout, probation, production, prolegomenon,
   proof, prove, put to trial, reading matter, recension, research,
   research paper, road-test, rough draft, rough sketch, run a sample,
   sample, screed, scrip, script, scrive, scroll, second draft, seek,
   shake down, shot, sketch, sounding out, special article, stab,
   standard, step, strive, striving, stroke, strong bid, struggle,
   study, substantiate, survey, tackle, taste, tentative, term paper,
   test, test case, the written word, theme, thesis, toil, touchstone,
   tract, tractate, transcript, transcription, travail, treatise,
   treatment, trial, trial and error, try, try it on, try out,
   typescript, undertake, undertaking, validate, venture, venture on,
   venture upon, verification, verify, version, whack, work,
   writing