The Collaborative International Dictionary of English v.0.48:

Hardly \Hard"ly\ (h[aum]rd"l[y^]), adv. [AS. heardlice. See
   Hard.]
   [1913 Webster]
   1. In a hard or difficult manner; with difficulty.
      [1913 Webster]

            Recovering hardly what he lost before. --Dryden.
      [1913 Webster]

   2. Unwillingly; grudgingly.
      [1913 Webster]

            The House of Peers gave so hardly their consent.
                                                  --Milton.
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   3. Scarcely; barely; not quite; not wholly.
      [1913 Webster]

            Hardly shall you find any one so bad, but he desires
            the credit of being thought good.     --South.
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   4. Severely; harshly; roughly.
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            He has in many things been hardly used. --Swift.
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   5. Confidently; hardily. [Obs.] --Holland.
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   6. Certainly; surely; indeed. [Obs.] --Chaucer.
      [1913 Webster]

WordNet (r) 3.0 (2006):

hardly
    adv 1: only a very short time before; "they could barely hear
           the speaker"; "we hardly knew them"; "just missed being
           hit"; "had scarcely rung the bell when the door flew
           open"; "would have scarce arrived before she would have
           found some excuse to leave"- W.B.Yeats [syn: barely,
           hardly, just, scarcely, scarce]
    2: almost not; "he hardly ever goes fishing"; "he was hardly
       more than sixteen years old"; "they scarcely ever used the
       emergency generator" [syn: hardly, scarcely]

Moby Thesaurus II by Grady Ward, 1.0:

107 Moby Thesaurus words for "hardly":
   a bit, a little, abnormally, arduously, at infrequent intervals,
   badly, barely, bitterly, burdensomely, by a hair, by an ace,
   by no means, closely, difficultly, energetically, ever so little,
   exiguously, faintly, feebly, fiercely, firmly, forcefully,
   forcibly, frenziedly, furiously, hardly ever, harshly, imperfectly,
   impliably, inappreciably, inconsequentially, incredibly,
   inexorably, inflexibly, infrequently, insignificantly,
   ironhandedly, just, just a bit, keenly, laboriously, lightly,
   little, madly, meagerly, might and main, mightily, minimally,
   minutely, narrowly, nearly, negligibly, not hardly, not often,
   not quite, obdurately, onerously, only, only just, painfully,
   powerfully, rancorously, rarely, relentlessly, rigidly, rigorously,
   roughly, scantily, scarce, scarcely, scarcely ever, seldom,
   seldom if ever, severely, slightly, solid, solidly, sorely,
   sparsely, stiffly, stormily, strenuously, strongly, tant soit peu,
   the hard way, toilsomely, triflingly, turbulently, unbendingly,
   uncommonly, uncompromisingly, uncustomarily, unexpectedly,
   unfrequently, unnaturally, unoften, unordinarily, unrelentingly,
   unusually, unyieldingly, very seldom, vigorously, violently,
   weakly, wildly, with difficulty, with much ado