memorandum

The word 'memorandum' is a direct borrowing from Latin, where it is the neuter singular form of the gerundive memorandus, meaning '(something) to be remembered'. It originates from the verb memorare ('to bring to mind, mention'), which itself derives from the root memor ('mindful'). This etymological path clearly illustrates the word's function: a memorandum is literally "a thing that must be remembered or brought to mind," serving as a formal written reminder. It entered English in the late 15th century, initially used in the Latin phrase 'memorandum est' ('it must be remembered'), before being lexicalized as a standalone noun for a note or record.

Structure: memor (mindful) + andum (thing to be done) 'memor' is from Latin memor, meaning 'mindful' or 'remembering'. '-andum' is the Latin gerundive suffix, forming a neuter noun meaning 'a thing to be done'.