memorandum
/ˌmeməˈrændəm/noun
(pl. memoranda /-də/ 或memorandums)
1- a note or record made for future use备忘录; 备忘便条：
the two countries signed a memorandum of understanding on economic cooperation.
两国签署了经济合作谅解备忘录。
1.1
- a written message, especially in business or diplomacy（尤指商业或外交的）备忘便条; 通报便条：
he told them of his decision in a memorandum.
他写备忘便条将决定告诉了他们。
1.2
- Law a document recording the terms of a contract or other legal details【律】合同书; 合约。
词源
late Middle English: from Latin, literally 'something to be brought to mind'， gerundive of memorare. The original use was as an adjective, placed at the head of a note of something to be remembered or of a record made for future reference.