dynamo
n. countablen. a machine that turns movement into electricity. It can also describe a person who has a huge amount of energy and never seems to stop working.
n. a machine that converts mechanical energy into electrical energy, typically through a rotating commutator. In a figurative sense, refers to an exceptionally energetic or productive person.
The old bicycle used a small dynamo to power its headlight.
The factory installed a large dynamo to ensure the machinery would keep running during a power cut.
The team's lead researcher is a literal dynamo, managing three separate projects while simultaneously publishing groundbreaking papers in international journals.
A shortening of dynamo-electric machine. The element dynamo- is ultimately from Ancient Greek δύναμις (dúnamis, “power”).
Countable in both its technical and figurative senses.