The Collaborative International Dictionary of English v.0.48:

Anxious \Anx"ious\ ([a^][ng]k"sh[u^]s), a. [L. anxius, fr.
   angere to cause pain, choke; akin to Gr. 'a`gchein to choke.
   See Anger.]
   1. Full of anxiety or disquietude; greatly concerned or
      solicitous, esp. respecting something future or unknown;
      being in painful suspense; -- applied to persons; as,
      anxious for the issue of a battle.
      [1913 Webster]

   2. Accompanied with, or causing, anxiety; worrying; --
      applied to things; as, anxious labor.
      [1913 Webster]

            The sweet of life, from which
            God hath bid dwell far off all anxious cares.
                                                  --Milton.
      [1913 Webster]

   3. Earnestly desirous; as, anxious to please.
      [1913 Webster]

            He sneers alike at those who are anxious to preserve
            and at those who are eager for reform. --Macaulay.
      [1913 Webster]

   Note: Anxious is followed by for, about, concerning, etc.,
         before the object of solicitude.
         [1913 Webster]

   Syn: Solicitous; careful; uneasy; unquiet; restless;
        concerned; disturbed; watchful.
        [1913 Webster]

WordNet (r) 3.0 (2006):

anxious
    adj 1: eagerly desirous; "anxious to see the new show at the
           museum"; "dying to hear who won" [syn: anxious(p),
           dying(p)]
    2: causing or fraught with or showing anxiety; "spent an anxious
       night waiting for the test results"; "cast anxious glances
       behind her"; "those nervous moments before takeoff"; "an
       unquiet mind" [syn: anxious, nervous, queasy, uneasy,
       unquiet]

Moby Thesaurus II by Grady Ward, 1.0:

135 Moby Thesaurus words for "anxious":
   aching, aghast, agitated, agog, alacritous, alarmed, all agog,
   all-overish, anguished, animated, annoyed, antsy, antsy-pantsy,
   anxioused up, apprehensive, ardent, athirst, avid, beset, bored,
   bothered, breathless, bursting to, careful, cautious, chafing,
   cheerless, concerned, depressed, desirous, disgusted, disquieted,
   distressed, disturbed, eager, edgy, embarrassed, enthusiastic,
   excited, fearful, foreboding, forward, fretful, fretting,
   frightened, full of life, grim, harassed, hasty, hopped-up,
   ill at ease, impatient, impetuous, importunate, in a lather,
   in a pucker, in a stew, in a sweat, in suspense, inconvenienced,
   irked, jittery, joyless, keen, keyed-up, lively, longing,
   misgiving, nauseated, nauseous, nervous, on edge, on tenterhooks,
   on tiptoe, overanxious, overapprehensive, panting, perturbed,
   plagued, pleasureless, pressing, prey to malaise, prompt,
   put to it, puzzled, qualmish, qualmy, quick, quivering, raring to,
   ready, ready and willing, repelled, restive, restless, revolted,
   sad, scared, scary, sickened, solicitous, sore beset, spirited,
   squirming, squirmy, strained, suffering angst, suspenseful, taut,
   tense, terrified, thirsty, troubled, uncertain, uneasy,
   unfulfilled, ungratified, unhappy, unpatient, unquiet, unsatisfied,
   upset, urgent, vexed, vital, vivacious, vivid, wary, watchful,
   with bated breath, with muscles tense, worried, yearning, zealous,
   zestful