A mimeograph is an old-fashioned copy machine. Mimeographs were often used for making classroom copies in schools before photocopying became inexpensive in the mid- to late-twentieth century.
A mimeograph printed copies by pressing ink through a stencil onto paper, which was pulled by a crank through a system of rollers. The copies themselves were often also called mimeographs. Even after the invention of modern photocopiers, mimeographs were a popular way to make cheap copies, and many offices still had the machines as late as the 1990's. The root of mimeograph is the Greek mimeisthai, "to mimic, represent, or imitate."