- an electric generator, especially for direct current
1882, short for Ger. dynamoelektrischemaschine, coined 1867 by its inventor, Ger. electrical engineer Werner Siemans (1816-92), from Gk. dynamis "power."
"Mercury and Earth both have an internal magnetic field similar to that of a giant magnet... Both fields are thought to be generated by core dynamos, where the electrically conducting, liquid iron is stirred by convective motion..., sustaining the magnetic lines of force."
- Julien Aubert, "Ancient planetary dynamos, take two: Magnetic studies of Earth and Mercury constrain their ancient core dynamics", Science 349:475 (31 July 3015)