The Collaborative International Dictionary of English v.0.48:

Specious \Spe"cious\, a. [L. speciosusgood-looking, beautiful,
   specious, fr. species look, show, appearance; cf. F.
   sp['e]coeux. See Species.]
   1. Presenting a pleasing appearance; pleasing in form or
      look; showy.
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            Some [serpents] specious and beautiful to the eye.
                                                  --Bp.
                                                  Richardson.
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            The rest, far greater part,
            Will deem in outward rites and specious forms
            Religion satisfied.                   --Milton.
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   2. Apparently right; superficially fair, just, or correct,
      but not so in reality; appearing well at first view;
      plausible; as, specious reasoning; a specious argument.
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            Misled for a moment by the specious names of
            religion, liberty, and property.      --Macaulay.
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            In consequence of their greater command of specious
            expression.                           --J. Morley.
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   Syn: Plausible; showy; ostensible; colorable; feasible. See
        Plausible.
        [1913 Webster] -- Spe"xious*ly, adv. --
        Spe"cious*ness, n.
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