- A device which periodically interrupts a direct current, light beam, or other signal. This may be done, for instance, to modulate, or to facilitate the amplification of an associated quantity.
- A device which periodically interrupts DC in order to produce AC.
- noun a helicopter. This was probably originally a children’s version of the longer word, reinforced by the sound and scything action of the rotor blades. It was adopted by adults in World War II.
- noun the penis. A working-class vulgarism dating from at least the 1940s and still heard.
- noun a machine gun. Although this use of the word is familiar to many people through films and crime fiction, it has been obsolete in spontaneous speech since before World War II.