dynamo

noun3

1. •
   An electricity generator; a dynamo-electric machine.

   • "As usual, it isn't telling the truth about it or you. But your body is. I can feel its vitality like the pulse of a dynamo." — 1950
2. •
   (figurative) An energetic person.

   • That new Vice President of Marketing is a real dynamo; sales have already gone up this quarter.
3. •
   The mechanism by which a celestial body, such as the Earth or a star, generates a magnetic field.