dynamo

Definitions

From Greek dynamis (power) — coined in the 1800s as a short name for a "power-making" machine. A dynamo turns spinning motion into electric power. The image of a humming, tireless power source carried over into the figurative sense: a human dynamo never seems to run out of energy.

Why It Means This

When 19th-century engineers built machines to turn motion into electricity, they reached for the Greek word for power, dynamis, and called them dynamos — literally "power-makers." Today generator is the usual word for the device, so dynamo survives most vividly in its figurative use: calling someone a dynamo means they radiate unstoppable energy, like a machine that never switches off.

Common Collocations

• 1.human dynamo人形发电机（精力旺盛的人）
• 2.little dynamo小能量包

Example Sentences

• 1.

  The old factory still ran on a dynamo that powered every machine on the floor.

• 2.

  She's a real dynamo, organizing three events while running her own company.

• 3.

  Spinning the wheel fast enough makes the bike's dynamo light up the lamp.