0 a machine that produces copies of a document using a stencil (= a piece of plastic or metal into which shapes have been cut, through which ink is forced): --
She kept mimeographs of every letter posted by her grandmother.
The first page is smeared with black ink like an old mimeograph.
What happened to the mimeograph machine on which your teacher cranked out those daunting tests?
If we needed to copy a document, we usually used a mimeograph or carbon paper.