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.]
The horse-chestnut is . . . ready to explain its
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.
Commentators to explain the difficult passages to
To explain away, to get rid of by explanation. "Those
explain the meaning quite away." --Pope.
Syn: To expound; interpret; elucidate; clear up.