amanuensis
noun (formal)a person who writes down your words when you cannot write, for example if you are injured and have an exam 代笔人；抄写员 an assistant, especially one who writes or types for somebody 助手；（尤指）秘书
Word Originearly 17th cent.: Latin, from (servus) a manu ‘(slave) at hand(writing), secretary’ + -ensis ‘belonging to’.