Source : Webster's Revised Unabridged Dictionary (1913)

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.

            An earnest advocate to plead for him. --Shak.

   2. Intent; fixed closely; as, earnest attention.

   3. Serious; important. [Obs.]

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

   Syn: Eager; warm; zealous; ardent; animated; importunate;
        fervent; sincere; serious; hearty; urgent. See {Eager}.

Earnest \Ear"nest\, n. [AS. eornost, eornest; akin to OHG.
   ernust, G. ernst; cf. Icel. orrosta battle, perh. akin to Gr.
   ? to excite, L. oriri to rise.]
   Seriousness; reality; fixed determination; eagerness;
   intentness.

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

         And given in earnest what I begged in jest. --Shak.

   {In earnest}, serious; seriously; not in jest; earnestly.

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

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

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.

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

            And from his coffers Received the golden earnest of
            our death.                            --Shak.

   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.

   {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.

Source : WordNet®

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: {in
            earnest(p)}, {sincere}, {solemn}]
     2: earnest; "one's dearest wish"; "devout wishes for their
        success"; "heartfelt condolences" [syn: {dear}, {devout},
        {heartfelt}]
     3: not distracted by anything unrelated to the goal [syn: {businesslike}]

earnest
     n : something of value given by one person to another to bind a
         contract