memorandum (n.)youdaoicibaDictYouDict[memorandum 词源字典]
early 15c., from Latin memorandum "(thing) to be remembered," neuter singular of memorandus "worthy of remembrance, noteworthy," gerundive of memorare "to call to mind," from memor "mindful of" (see memory). Originally a word written at the top of a note, by 1540s it came to stand for the note itself. The Latin plural is memoranda. Compare also agenda.[memorandum etymology, memorandum origin, 英语词源]