The Collaborative International Dictionary of English v.0.48:

Explain \Ex*plain"\ ([e^]ks*pl[=a]n"), v. t. [imp. & p. p.
   Explained([e^]ks*pl[=a]nd"); p. pr. & vb. n. Explaining.]
   [L. explandare to flatten, spread out, explain; ex out +
   plandare to make level or plain, planus plain: cf. OF.
   esplaner, explaner. See Plain,a., and cf. Esplanade.]
   1. To flatten; to spread out; to unfold; to expand. [Obs.]
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            The horse-chestnut is . . . ready to explain its
            leaf.                                 --Evelyn.
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   2. To make plain, manifest, or intelligible; to clear of
      obscurity; to expound; to unfold and illustrate the
      meaning of; as, to explain a chapter of the Bible.
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            Commentators to explain the difficult passages to
            you.                                  --Gay.
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   To explain away, to get rid of by explanation. "Those
      explain the meaning quite away." --Pope.

   Syn: To expound; interpret; elucidate; clear up.
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