Here's the breakdown:
* "agendum" (singular): This means "thing to be done" or "matter to be acted upon". It comes from the verb "agere", which means "to do" or "to act".
* "agenda" (plural): This means "things to be done" or "matters to be acted upon", effectively a list of items to be considered.
So, the word "agenda" has been directly adopted into English from its Latin form.