Definitions
1.NounA device, at least partially mechanical, used to print text by pressing keys that cause type to be impressed through an inked ribbon onto paper.
2.NounOne who uses a typewriter; a typist.
3.NounA machine gun or submachine gun (from the noise it makes when firing).
4.NounA prank in which fingers are jabbed roughly onto someone's chest followed by striking them over the ear in imitation of using an old-fashioned typewriter.