The Collaborative International Dictionary of English v.0.48:

Aston \As*ton"\, Astone \As*tone"\, v. t. [imp. & p. p.
   Astoned, Astond, or Astound.] [See Astonish.]
   To stun; to astonish; to stupefy. [Obs.] --Chaucer.
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The Collaborative International Dictionary of English v.0.48:

Astound \As*tound"\, a. [OE. astouned, astound, astoned, p. p.
   of astone. See Astone.]
   Stunned; astounded; astonished. [Archaic] --Spenser.
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         Thus Ellen, dizzy and astound.
         As sudden ruin yawned around.            --Sir W.
                                                  Scott.
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The Collaborative International Dictionary of English v.0.48:

Astound \As*tound"\, v. t. [imp. & p. p. Astounded, [Obs.]
   Astound; p. pr. & vb. n. Astounding.] [See Astound, a.]
   1. To stun; to stupefy.
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            No puissant stroke his senses once astound.
                                                  --Fairfax.
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   2. To astonish; to strike with amazement; to confound with
      wonder, surprise, or fear.
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            These thoughts may startle well, but not astound
            The virtuous mind.                    --Milton.
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WordNet (r) 3.0 (2006):

astound
    v 1: affect with wonder; "Your ability to speak six languages
         amazes me!" [syn: amaze, astonish, astound]