The Oxford Thesaurus An A-Z Dictionary of Synonyms - explain v.

1) interpret, define, explicate, detail, delineate, make plain, simplify, spell out, resolve, get across, clarify, clear up, elucidate, illustrate, expound, describe, disclose, unfold, unravel, untangle: The teacher explained the theory so that even I could understand it. 2) Also, explain away. justify, account for, excuse, rationalize, legitimate, legitimatize, extenuate, palliate: You will be required to explain your absence.