hydrology

Etymology

It is borrowed from New Latin hydrologia,^[2][3][4] formed from hydro- and -logia,^[2][3] from Ancient Greek ὑδρο- (hudro-), the combining form of ὕδωρ (húdōr, “water”),^[2] and -λογία (-logía).^[5] The Greek word for water comes from the same Indo-European base as water.^[2] Etymonline and Dictionary.com take it as formed in English from hydro- and -logy.^[6][7] The OED notes that the Latin word was cited as the title of a 1586 work by Marcus Antonius Marsilius, archbishop of Salerno, on the properties of holy waters (its real title was “Hydragiologia”), and later as the title of a work on seas and lakes (1634), and compares French hydrologie, recorded from 1614.^[2]

Earliest recorded meaning

The study of the properties of water: 1680, in J. Peter's Treatise of Lewisham Wells.^[2] Etymonline and Merriam-Webster Unabridged date the word to 1762.^[6][3]

Semantic evolution

The word began in the 17th century as the study of water and its properties, often with an eye to mineral springs, and in 1757 it was used in medicine for treatment by drinking or bathing in mineral waters, a use now historical.^[2][4] In later use it became the science of water on and under the earth's surface and in the atmosphere, its distribution and circulation through evaporation and precipitation,^[2][3][8] and also the water features of a particular region.^[3][4] A different English hydrologie, recorded in 1659, was a water clock, from Ancient Greek ὑδρολόγιον (hudrológion).^[2] Etymonline records the adjective hydrological from the 1660s.^[6]

Timeline

• 1680 – the study of water and its properties.^[2]
• 1757 – in medicine, treatment with mineral waters.^[2]
• 1762 – the science of water.^[6][3]

Meanings

Noun

1. The science of the properties, distribution and circulation of water, especially of water on the land surface, in the soil and rocks beneath it, and in the atmosphere.^[3][8][2]
2. The water features of a region, such as its precipitation, streams and groundwater: the hydrology of the delta.^[3][4]
3. (historical) Medical treatment by drinking or bathing in mineral waters.^[2][4]

Word family

• hydrologic
• hydrologically
• hydrologist
• geohydrology
• hydrological

Related words

• hydro-
• -logy
• water

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
4. ^ a b c d e Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
6. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
8. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins