An amanuensis (/əˌmænjuːˈɛnsɪs/) is a person employed to write or type what another dictates or to copy what has been written by another, and also refers to a person who signs a document on behalf of another under the latter's authority.
The word originated in ancient Rome, for a slave at his master's personal service "within hand reach", performing any command; later it was specifically applied to an intimately trusted servant (often a freedman) acting as a personal secretary (amanuensis is what he does, not what he is).
A similar semantic evolution occurred at the French royal court, where the secrétaire de la main du roi, originally a lowly clerk specializing in producing, at royal command, the Sovereign's signature on more documents than he cared to put his pen to, developed into the secrétaires d'état, the first permanent portfolio ministers, to which the British Secretaries of State would be the counterpart.
The term is often used interchangeably with secretary or scribe.
It is also used in a specific sense in some academic contexts, for instance when an injured or disabled person is helped by an amanuensis at a written examination. A notable case in classical music was that of Eric Fenby, who assisted the blind composer Frederick Delius in writing down the notes that Delius dictated.