memorandum是如何构词呢？
和memory是一个词根么？是什么词根呀？

memorandum
mem.o.ran.dum
AHD:[mµm”…-r²n“d…m]
D.J.[7mem*6r#nd*m]
K.K.[7mWm*6r#nd*m]
n.（名词）
【复数】 me.mo.ran.dums 或 me.mo.ran.da [-d…] 缩写 mem.
A short note written as a reminder.
备忘便条：作为提醒之物的短笺
A written record or communication, as in a business office.
备忘录：（如一商业机构的）书面记录或交流
Law A short written statement outlining the terms of an agreement, a transaction, or a contract.
【法律】 交易备忘录：一简要的书面申明，记载有一协议交易或合同的各项条件摘要
A business statement made by a consignor about a shipment of goods that may be returned.
代销委托书：承销人所作之商务声明，载明退还货物的运输事项
A brief, unsigned diplomatic communication.
外交备忘录：简明的未经签署的外交公文

Middle English [to be remembered: used as a manuscript notation]
中古英语 [被记住，用作书面语]
from Latin [neuter sing. gerundive of] memor³re [to bring to remembrance] * see memorable
源自 拉丁语 [] memor³re的中性单数动形词 [纪念，记住] *参见 memorable
词根是memor³re 。