Jump to:

• 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.

---

Watt ² American  

[wot] / wɒt /

noun

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

---

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

---

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

---

watt ¹ 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).

---

Watt ² 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.

---

watt Cultural  

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

---

Etymology

Origin of watt

First recorded in 1882; named after J. Watt

Example Sentences

Young viewers will also be able to print and cut out their own Watt and Windy on the PBS Kids website and take them on trips to their own local landmarks.

From Los Angeles Times • May 21, 2026

Another series, “City Island: USA!,” is a special of six shorts, following Watt, a light bulb, and his best friend, Windy, a kite.

From Los Angeles Times • May 21, 2026

When he was chief economist of HSBC’s Canada unit, David Watt said he heard myriad anecdotes from clients about logjams at Canada’s ports.

From The Wall Street Journal • May 8, 2026

In fact, it was McCartney who introduced Watt to the Stones ahead of their 2023 comeback album Hackney Diamonds.

From BBC • Mar. 26, 2026

By 1800 only 2,200 steam engines had been built in Britain, some two thirds of which were Newcomen engines, and a quarter Boulton and Watt engines.

From "The Invention of Science" by David Wootton