The Collaborative International Dictionary of English v.0.48:

Eager \Ea"ger\, a. [OE. egre sharp, sour, eager, OF. agre,
   aigre, F. aigre, fr. L. acer sharp, sour, spirited, zealous;
   akin to Gr. ? highest, extreme, Skr. a?ra point; fr. a root
   signifying to be sharp. Cf. Acrid, Edge.]
   1. Sharp; sour; acid. [Obs.] "Like eager droppings into
      milk." --Shak.
      [1913 Webster]

   2. Sharp; keen; bitter; severe. [Obs.] "A nipping and an
      eager air." "Eager words." --Shak.
      [1913 Webster]

   3. Excited by desire in the pursuit of any object; ardent to
      pursue, perform, or obtain; keenly desirous; hotly
      longing; earnest; zealous; impetuous; vehement; as, the
      hounds were eager in the chase.
      [1913 Webster]

            And gazed for tidings in my eager eyes. --Shak.
      [1913 Webster]

            How eagerly ye follow my disgraces!   --Shak.
      [1913 Webster]

            When to her eager lips is brought
            Her infant's thrilling kiss.          --Keble.
      [1913 Webster]

            A crowd of eager and curious schoolboys.
                                                  --Hawthorne.
      [1913 Webster]

            Conceit and grief an eager combat fight. --Shak.
      [1913 Webster]

   4. Brittle; inflexible; not ductile. [Obs.]
      [1913 Webster]

            Gold will be sometimes so eager, as artists call it,
            that it will as little endure the hammer as glass
            itself.                               --Locke.

   Syn: Earnest; ardent; vehement; hot; impetuous; fervent;
        intense; impassioned; zealous; forward.

   Usage: See Earnest. -- Eager, Earnest. Eager marks an
          excited state of desire or passion; thus, a child is
          eager for a plaything, a hungry man is eager for food,
          a covetous man is eager for gain. Eagerness is liable
          to frequent abuses, and is good or bad, as the case
          may be. It relates to what is praiseworthy or the
          contrary. Earnest denotes a permanent state of mind,
          feeling, or sentiment. It is always taken in a good
          sense; as, a preacher is earnest in his appeals to the
          conscience; an agent is earnest in his solicitations.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Eager \Ea"ger\, n.
   Same as Eagre.
   [1913 Webster]

WordNet (r) 3.0 (2006):

eager
    adj 1: having or showing keen interest or intense desire or
           impatient expectancy; "eager to learn"; "eager to travel
           abroad"; "eager for success"; "eager helpers"; "an eager
           look" [ant: uneager]
    n 1: a high wave (often dangerous) caused by tidal flow (as by
         colliding tidal currents or in a narrow estuary) [syn:
         tidal bore, bore, eagre, aegir, eager]

Moby Thesaurus II by Grady Ward, 1.0:

170 Moby Thesaurus words for "eager":
   accordant, acquiescent, acquisitive, affirmative, agape, agog,
   agreeable, agreeing, alacritous, all agog, ambitious, amenable,
   animated, anticipant, anticipating, anticipative, anticipatory,
   antsy, antsy-pantsy, anxious, appetitive, approving, ardent,
   assenting, athirst, avid, awaiting, breathless, bursting to,
   certain, chafing, compliable, compliant, confident, consentient,
   consenting, content, cooperative, covetous, craving, desiderative,
   desireful, desiring, desirous, disposed, docile, dying, earnest,
   edgy, endorsing, energetic, energized, enthusiastic, excited,
   expectant, expecting, fain, favorable, favorably disposed,
   favorably inclined, fervent, fervid, forearmed, forestalling,
   forewarned, forward, fretful, fretting, full of life, game, gaping,
   gung ho, hankering, hasty, heated, honing, hopeful, hoping,
   hopped-up, hormic, hot, hungry, impatient, impetuous, in a lather,
   in a stew, in a sweat, in anticipation, in expectation,
   in the mind, in the mood, inclined, inspirited, intent, itchy,
   keen, lascivious, libidinal, libidinous, lickerish, lively,
   longing, looking for, looking forward to, lustful, minded, needing,
   not surprised, nothing loath, on edge, optative, optimistic,
   panting, passionate, permissive, pining, pliant, predisposed,
   prepared, prompt, prone, quick, raring, raring to, ratifying,
   ready, ready and willing, receptive, responsive, restive, restless,
   sanctioning, sanguine, solicitous, spirited, squirming, squirmy,
   stimulated, submissive, sure, tempted, thirsty, tractable, uneasy,
   ungrudging, unloath, unpatient, unquiet, unrefusing, unreluctant,
   unsurprised, vehement, vital, vitalized, vivacious, vivid, waiting,
   waiting for, wanting, watching for, well-disposed, well-inclined,
   willed, willing, willinghearted, wishful, wishing, yearning,
   zealous, zestful