Webster’s Revised Unabridged Dictionary · 1913
Explain
Ex·plain′ (ĕks·plān′), v. t. [imp. & p. p. Explained(- plānd′); 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 leaf. Evelyn.
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 you. Gay.
To explain away, to get rid of by explanation. "Those explain the meaning quite away." Pope.
Syn. — To expound; interpret; elucidate; clear up.
Ex·plain′, v. i. To give an explanation.