1
general::
Dismiss or minimize the importance of something, especially something detrimental. For example, "His words were taken down, and though he tried to explain them away, he was sent to the Tower" (Thomas Macaulay, The History of England, 1855). [c. 1700]
American Heritage Idioms
2
general::
Phrase(s): explain something away
to explain something so that it is no longer a problem. • You can try to explain it away if you want, but that won’t solve the problem. • You can’t just explain away all your problems.
McGrawhill's American Idioms And Phrasal Verbs