hydropower

Etymology

It is a compound from English hydro- + power,^[2][3][4] with hydro- standing for hydroelectric;^[2][3] Merriam-Webster Unabridged takes it as short for the phrase “hydroelectric power”.^[5] The prefix hydro- is from Ancient Greek ὑδρο- (hudro-), the combining form of ὕδωρ (húdōr, “water”).^[2][3]

Earliest recorded meaning

The power of moving or falling water, especially as used to generate electricity: 1906, in the Baltimore Sun.^[2]

Semantic evolution

Other dictionaries date the word later: Etymonline dates it to 1922, Merriam-Webster Unabridged to 1933 and Dictionary.com to 1930–35.^[3][5][4] Besides the power of the water itself, it came to mean, chiefly in the United States, the electricity generated from it.^[2]

Timeline

• 1906 – the power of moving water, harnessed to generate electricity.^[2] Etymonline dates the word to 1922 and Merriam-Webster Unabridged to 1933.^[3][5]

Meanings

Noun

1. Hydroelectric power: electricity generated from the energy of falling or flowing water.^[5][6][2]
2. The power of moving water as harnessed for this.^[2]

Related words

• hydroelectric

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
5. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ Collins English Dictionary (2023), Glasgow: HarperCollins