An amanuensis is someone who is good at taking notes when someone else is talking, like a secretary.
In Latin, the word amanuensis literally means "a servant from the hand." The word generally refers to a person who is skilled at taking dictation. In a courtroom, you might see a stenographer quickly typing up what everyone in the room is saying. A stenographer is an amanuensis. Anyone who can copy or write down what someone else is saying is considered an amanuensis. So if you've ever taken good notes in class, then you're an amanuensis!