The Collaborative International Dictionary of English v.0.48:

Attenuate \At*ten"u*ate\, v. t. [imp. & p. p. Attenuated; p.
   pr. & vb. n. Attenuating.] [L. attenuatus, p. p. of
   attenuare; ad + tenuare to make thin, tenuis thin. See
   Thin.]
   1. To make thin or slender, as by mechanical or chemical
      action upon inanimate objects, or by the effects of
      starvation, disease, etc., upon living bodies.
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   2. To make thin or less consistent; to render less viscid or
      dense; to rarefy. Specifically: To subtilize, as the
      humors of the body, or to break them into finer parts.
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   3. To lessen the amount, force, or value of; to make less
      complex; to weaken.
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            To undersell our rivals . . . has led the
            manufacturer to . . . attenuate his processes, in
            the allotment of tasks, to an extreme point. --I.
                                                  Taylor.
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            We may reject and reject till we attenuate history
            into sapless meagerness.              --Sir F.
                                                  Palgrave.
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