reckoning (n.)youdaoicibaDictYouDict[reckoning 词源字典]
early 14c., "narrative, account," verbal noun from reckon (v.). Meaning "a settling of accounts" is from mid-14c.; that of "calculation" is from late 14c. Compare Dutch rekening "a bill, account, reckoning," Old High German rechenunga, German rechnung, Danish regning "a reckoning, computation." Day of reckoning attested from c. 1600.[reckoning etymology, reckoning origin, 英语词源]