# dynamo

/ˈdaɪnəˌmoʊ/ (US) · /dˈaɪnɐmˌəʊ/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/dynamo
Updated: 2026-05-08

## Definition

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.

For teachers: 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.

## Examples

- 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.

## Usage notes

- Countable in both its technical and figurative senses.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.