Late Middle English: from Latin commemoratio(n-), from the verb commemorare 'bring to remembrance' (see commemorate).

• memory from Middle English:

  English adopted the Latin word memoria twice, first directly from Latin in the Middle Ages as memory, then in the 15th century through French as memoir. The earliest sense of memoir was ‘a memorandum’; people's memoirs, either recording historical events or recounting their own lives, appeared in the 17th century. Latin memoria is formed from memor ‘mindful’, from which memorable (Late Middle English); remember (Middle English); remind (mid 17th century); reminisce (early 19th century); and commemoration (Late Middle English) also come. A 1903 song introduced the world to memory lane, while another song took the same title in 1924. In both lyrics people ‘wandered’, whereas nowadays we take a trip down memory lane when we indulge in pleasant or sentimental memories. In medieval times and later, merchants, lawyers, and diplomats would write memorandum that… at the head of a note of something to be remembered or a record of what had been done. In Latin memorandum means ‘it is to be remembered’, and is a form of memorare, ‘to bring to mind’. Memento (Late Middle English) is also pure Latin. It was at first a prayer of commemoration and is an order to ‘remember!’.