dy·​na·​mo | \ ˈdī-nə-ˌmō How to pronounce dynamo (audio) \
plural dynamos

Definition of dynamo

2 : a forceful energetic individual

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Synonyms for dynamo


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The dynamo was introduced in 1867 to produce electricity for commercial use. Like all later generators, the original dynamos changed mechanical energy (produced by steam, which was itself produced by burning coal) into electricity. The word is less used today than it once was, since it's often applied only to generators that produced direct electric current (DC) rather than alternating current (AC), which is now the standard. A human dynamo is a person who seems to have unlimited energy.

Examples of dynamo in a Sentence

a dynamo who barely needs to sleep, or so it seems
Recent Examples on the Web In the body politic, companies are the strong arms which turn the dynamo of growing productivity, not the mouth which lectures the world on politics. Jerry Bowyer, National Review, 6 July 2021 Germany, however, suffered without its dynamo on the left. Manuel Veth, Forbes, 19 June 2021 Of these, Mary proved to be a true dynamo, making unmatched contributions to Carroll County. Frank Batavick, baltimoresun.com/maryland/carroll, 11 June 2021 Along with his father’s love, the other constant in the boy’s life—and the thing Mr. Tougias credits with saving him from more serious trouble—is his love of the outdoors, a dynamo of fascination and adventure, a place that draws him back endlessly. Bill Heavey, WSJ, 26 May 2021 On social media, Myles was a dynamo and in a few short weeks this March raised almost $40,000 for the group’s legal-defense fund. Keith Gessen, Curbed, 10 May 2021 Due to the much smaller size of Mars compared to Earth, its core cooled much more rapidly, eventually leading to the death of the internal magnetic dynamo that actively diverts those solar particles away. Ethan Siegel, Forbes, 16 Apr. 2021 The small band of strings under Sorrell was plenty lively, but Choo was a dynamo, often driving the tempo and always delivering lines with panache. Zachary Lewis, cleveland, 22 Apr. 2021 Sometimes redefining success is needed, especially against a dynamo like Curry. Chris Fedor, cleveland, 16 Apr. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'dynamo.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of dynamo

1882, in the meaning defined at sense 1

History and Etymology for dynamo

short for dynamo-electric machine, translation of German dynamo-elektrische Maschine; dynamo-elektrisch, probably by inversion of elektrodynamisch electrodynamic

Note: According to the Oxford English Dictionary (1st edition, 1897), "The full name dynamo-electric machine was given by [Werner] Siemens in 1867, to distinguish his invention from the magneto-electric machines previously used, in which the electric current was generated by means of a permanent magnet." This statement appears to be based on a citation from The Times (December 5, 1882), according to which, "Professor Thompson [not further identified] said that the name 'dynamo-electric machine' was first applied by Dr. Werner Siemens in a communication made in January, 1867, to the Berlin Academy." The communication in question was "Ueber die Umwandlung von Arbeitskraft in elektrischen Strom ohne Anwendung permanenter Magnete," published in Annalen der Physik und Chemie, Band 130 (1867), pp. 332-35. The article does in fact describe a generator with rotating coils, but nowhere does Siemens use the word dynamo-elektrisch or the phrase dynamo-elektrische Maschine; the closest he comes is magnetelektrisch for the opposing term. The first appearance of dynamo-elektrisch must date some time after this.

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Last Updated

18 Jul 2021

Cite this Entry

“Dynamo.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dynamo. Accessed 24 Jul. 2021.

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More Definitions for dynamo



English Language Learners Definition of dynamo

: a machine that produces electricity
informal : someone who has a lot of energy


dy·​na·​mo | \ ˈdī-nə-ˌmō How to pronounce dynamo (audio) \
plural dynamos

Kids Definition of dynamo

1 : generator
2 : an energetic person

More from Merriam-Webster on dynamo

Nglish: Translation of dynamo for Spanish Speakers

Britannica.com: Encyclopedia article about dynamo


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