dynamo
n.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.”
Countable in both its technical and figurative senses.
“Cape Verde’s cult hero Vozinha now keeps net for the Chilean giants Colo-Colo and Morocco’s attacking dynamo, Ismael Saibari, has rocked up at Bayern.”
“The interaction between the solar wind and Earth's magnetosphere can be thought of as a giant dynamo.”
A shortening of dynamo-electric machine. The element dynamo- is ultimately from Ancient Greek δύναμις (dúnamis, “power”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.