The Collaborative International Dictionary of English v.0.48:

Earnest \Ear"nest\ ([~e]r"n[e^]st), n. [AS. eornost, eornest;
   akin to OHG. ernust, G. ernst; cf. Icel. orrosta battle,
   perh. akin to Gr. 'orny`nai to excite, L. oriri to rise.]
   Seriousness; reality; fixed determination; eagerness;
   intentness.
   [1913 Webster]

         Take heed that this jest do not one day turn to
         earnest.                                 --Sir P.
                                                  Sidney.
   [1913 Webster]

         And given in earnest what I begged in jest. --Shak.
   [1913 Webster]

   In earnest, serious; seriously; not in jest; earnestly.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Earnest \Ear"nest\, a.
   1. Ardent in the pursuit of an object; eager to obtain or do;
      zealous with sincerity; with hearty endeavor; heartfelt;
      fervent; hearty; -- used in a good sense; as, earnest
      prayers.
      [1913 Webster]

            An earnest advocate to plead for him. --Shak.
      [1913 Webster]

   2. Intent; fixed closely; as, earnest attention.
      [1913 Webster]

   3. Serious; important. [Obs.]
      [1913 Webster]

            They whom earnest lets do often hinder. --Hooker.

   Syn: Eager; warm; zealous; ardent; animated; importunate;
        fervent; sincere; serious; hearty; urgent. See Eager.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Earnest \Ear"nest\, v. t.
   To use in earnest. [R.]
   [1913 Webster]

         To earnest them [our arms] with men.     --Pastor Fido
                                                  (1602).
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Earnest \Ear"nest\, n. [Prob. corrupted fr. F. arrhes, L. arra,
   arrha, arrhabo, Gr. 'arrabw`n, of Semitic origin, cf. Heb.
   [=e]r[=a]v[=o]n; or perh. fr. W. ernes, akin to Gael. earlas,
   perh. fr. L. arra. Cf. Arles, Earles penny.]
   1. Something given, or a part paid beforehand, as a pledge;
      pledge; handsel; a token of what is to come.
      [1913 Webster]

            Who hath also sealed us, and given the earnest of
            the Spirit in our hearts.             --2 Cor. i.
                                                  22.
      [1913 Webster]

            And from his coffers
            Received the golden earnest of our death. --Shak.
      [1913 Webster]

   2. (Law) Something of value given by the buyer to the seller,
      by way of token or pledge, to bind the bargain and prove
      the sale. --Kent. Ayliffe. Benjamin.
      [1913 Webster]

   Earnest money (Law), money paid as earnest, to bind a
      bargain or to ratify and prove a sale.

   Syn: Earnest, Pledge.

   Usage: These words are here compared as used in their
          figurative sense. Earnest is not so strong as pledge.
          An earnest, like first fruits, gives assurance, or at
          least a high probability, that more is coming of the
          same kind; a pledge, like money deposited, affords
          security and ground of reliance for the future.
          Washington gave earnest of his talent as commander by
          saving his troops after Braddock's defeat; his
          fortitude and that of his soldiers during the winter
          at Valley Forge might rightly be considered a pledge
          of their ultimate triumph.
          [1913 Webster]

WordNet (r) 3.0 (2006):

earnest
    adj 1: characterized by a firm and humorless belief in the
           validity of your opinions; "both sides were deeply in
           earnest, even passionate"; "an entirely sincere and cruel
           tyrant"; "a film with a solemn social message" [syn:
           earnest, sincere, solemn]
    2: earnest; "one's dearest wish"; "devout wishes for their
       success"; "heartfelt condolences" [syn: dear, devout,
       earnest, heartfelt]
    3: not distracted by anything unrelated to the goal [syn:
       businesslike, earnest]
    n 1: something of value given by one person to another to bind a
         contract

Moby Thesaurus II by Grady Ward, 1.0:

195 Moby Thesaurus words for "earnest":
   abandoned, acquitment, acquittal, acquittance, advertent, afire,
   agog, alert, all ears, all eyes, amortization, amortizement,
   ardent, assiduous, attention, attentive, aware, awe-inspiring,
   bail, binder, bond, bound, bound and determined, burning, busy,
   careful, cash, cash payment, clearance, committed, concentrated,
   conscientious, conscious, debt service, decided, decisive,
   decorous, dedicated, definite, defrayal, defrayment, demure,
   deposit, determined, devoted, devout, diligent, disbursal,
   discharge, doling out, down payment, eager, earnest money,
   enthusiasm, enthusiastic, escrow, faithful, fatal, fateful,
   fervent, fervid, fiery, finical, finicking, finicky, firm, flaming,
   formal, formidable, frowning, gage, grave, grim, grim-faced,
   grim-visaged, guarantee, handsel, hard-working, hearty, heated,
   heavy, heedful, hire purchase, hire purchase plan, hock, hostage,
   hot, hot-blooded, impassioned, imposing, in earnest, industrious,
   installment, installment plan, intense, intent, intent on,
   intentive, intentness, interest, interest payment, keen,
   liquidation, long-faced, loyal, mainprise, meticulous, mindful,
   monthly payments, never-never, nice, niggling, no-nonsense,
   observant, observing, obstinate, on fire, on the ball, on the job,
   open-eared, open-eyed, openmouthed, passionate, pawn, paying,
   paying off, paying out, paying up, payment, payment in kind,
   payoff, perfervid, perseverant, persevering, persistent, pignus,
   pledge, portentous, prepayment, pressing, purposeful,
   quarterly payments, quittance, recognizance, red-hot, regardful,
   regular payments, relentless, remittance, replevin, replevy,
   resolute, resolved, retirement, satisfaction, security, sedate,
   sedulous, serious, seriousness, settlement, sincere, single-minded,
   sinking-fund payment, sober, sober-minded, sobersided, solemn,
   somber, spirited, spot cash, staid, steady, stone-faced,
   straight-faced, surety, tenacious, thoughtful, token,
   token payment, undertaking, unsmiling, vadimonium, vadium,
   vehement, warm, warmth, warrant, watchful, weekly payments,
   weighty, white-hot, wholehearted, zeal, zealous



Easton's 1897 Bible Dictionary:

Earnest
   The Spirit is the earnest of the believer's destined inheritance
   (2 Cor. 1:22; 5:5; Eph. 1:14). The word thus rendered is the
   same as that rendered "pledge" in Gen. 38:17-20; "indeed, the
   Hebrew word has simply passed into the Greek and Latin
   languages, probably through commercial dealings with the
   Phoenicians, the great trading people of ancient days.
   Originally it meant no more than a pledge; but in common usage
   it came to denote that particular kind of pledge which is a part
   of the full price of an article paid in advance; and as it is
   joined with the figure of a seal when applied to the Spirit, it
   seems to be used by Paul in this specific sense." The Spirit's
   gracious presence and working in believers is a foretaste to
   them of the blessedness of heaven. God is graciously pleased to
   give not only pledges but foretastes of future blessedness.


Bouvier's Law Dictionary, Revised 6th Ed (1856):

EARNEST, contracts. The payment of a part of the price of goods sold, or the
delivery of part of such goods, for the purpose of binding the contract.
     2. The effect of earnest is to bind the goods sold, and upon their
being paid for without default, the buyer is entitled to them. But
notwithstanding the earnest, the money must be paid upon taking away the
goods, because no other time for payment is appointed; earnest only binds
the bargain, and gives the buyer a right to demand, but a demand without
payment of the money is void; after earnest given the vendor cannot sell the
goods to another, without a default in the vendee, and therefore if the
latter does not come and pay, and take the goods, the vendor ought to go and
request him, and then if he does not come, pay for the goods and take them
away in convenient time, the agreement is dissolved, and he is at liberty to
sell them to any other person. 1 Salk. 113: 2 Bl. Com. 447; 2 Kent, Com.
389; Ayl. Pand. 450; 3 Campb. R. 426.