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• watt
  watt

  noun

  the standard unit of power in the International System of Units (SI), equivalent to one joule per second and equal to the power in a circuit in which a current of one ampere flows across a potential difference of one volt. W, w.
• Watt
  Watt

  noun

  James, 1736–1819, Scottish engineer and inventor.

watt

¹ American  

[wot] / wɒt /

noun

1. the standard unit of power in the International System of Units (SI), equivalent to one joule per second and equal to the power in a circuit in which a current of one ampere flows across a potential difference of one volt. W, w.

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Watt ² American  

[wot] / wɒt /

noun

1. James, 1736–1819, Scottish engineer and inventor.

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Watt ¹ British  

/ wɒt /

noun

1. James. 1736–1819, Scottish engineer and inventor. His fundamental improvements to the steam engine led to the widespread use of steam power in industry

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watt ² British  

/ wɒt /

noun

1.  W.  the derived SI unit of power, equal to 1 joule per second; the power dissipated by a current of 1 ampere flowing across a potential difference of 1 volt. 1 watt is equivalent to 1.341 × 10 ^–3 horsepower

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Watt ¹ Scientific  

1. British engineer and inventor who patented a much improved version of the steam engine (1769) and devised the unit of horsepower. The watt unit of power is named for him.

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watt ² Scientific  

/ wŏt /

1. The SI derived unit used to measure power, equal to one joule per second. In electricity, a watt is equal to current (in amperes) multiplied by voltage (in volts).

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watt Cultural  

1. The basic unit of power, named after the eighteenth-century Scottish inventor James Watt.

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Etymology

Origin of watt

First recorded in 1882; named after J. Watt

Example Sentences

Ayar Labs says its interconnection chips can provide between four and 20 times the computing throughput per watt of energy spent to power an AI processor, compared with chips that use copper interconnects.

From The Wall Street Journal • Mar. 3, 2026

Nvidia said its CPUs offer an improvement in performance per watt for Meta’s data centers, which Windsor noted is becoming more crucial to the data-center buildout as worries mount over electrical-grid capacity.

From MarketWatch • Feb. 18, 2026

It said 18A offers up to 15% better performance per watt and 30% better chip density versus the prior Intel 3 process.

From Barron's • Oct. 9, 2025

Massey is especially annoyed Dominion ratepayers are already on the hook to pay for the nuclear plants that never generated a watt of power and are being asked to pay for another power plant.

From Seattle Times • May 8, 2024

When he has to step over a rope or an air-tnbe on deck, it is hard work—like climbing a watt.

From "The Once and Future King" by T. H. White