Elements of the Universe: Hydr, Hydro ("Water")

The ancients believed that the universe was composed of five basic elements: earth, air, fire, water, and sky. The Greek and Latin words for these elements still show up in our language today. Learn these words that come from the Greek word hydor, meaning "water."

Here are links to our complete set of Elements of the Universe lists: Cosm, Cosmo ("Universe") / Terr, Terra ("Earth") / Geo ("Earth") / Hydr, Hydro ("Water") / Aqua ("Water") / Ign, Igni ("Fire") / Pyr, Pyro ("Fire") / Aer, Aero ("Air") / Aether ("Sky") / Aster, Astro ("Star") / Sol ("Sun")
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Full list of words from this list:

words only definitions & notes
  1. carbohydrate
    an essential component of living cells and source of energy
    Thanks to chlorophyll, plants are able to transform sunlight, water, and minerals into carbohydrates. The Omnivore's Dilemma
  2. hydra
    small tubular solitary freshwater hydrozoan polyp
    Boldly rendered sea creatures, including hydras, cephalopods, nautiluses and various extinct invertebrates parade across raw cotton in striking gray ink. Scientific American
    In Greek mythology, the Hydra is a serpent-like monster that lives in water. If one of the Hydra's many heads was cut off, two more would grow in its place. By extension, the word has come to refer to any multifaceted problem that is difficult to solve.
  3. hydrant
    a discharge pipe with a valve and spout at which water may be drawn from the mains of waterworks
    But the words were coming out of him like the water spraying from a broken fire hydrant in summer, and he could not have stopped them if he had tried. American Gods
  4. hydrate
    add water or moisture to
    That means I need more surface area for farming, and more water to hydrate the soil. The Martian
  5. dehydrate
    preserve by removing all water and liquids from
    “Food for two weeks— dehydrated. You just drop one of these into the purifier and add water. Any kind of water.” Uglies
  6. dehydrated
    suffering from excessive loss of water from the body
    Already the heat blazed down on us with a vengeance, and we were so dehydrated our tongues felt like thick, dry parchments in our mouths. Summer of the Mariposas
  7. dehydration
    dryness resulting from the removal of water
    “Your skin is still elastic, which means your dehydration isn’t critical yet.” Dry
  8. hydrophobia
    a symptom of rabies consisting of an aversion to liquids
    And I was so scared and mixed up about the danger of hydrophobia that it was clear into the next day before I even thought about thanking him for giving us Old Yeller. Old Yeller
    hydor + phobos ("fear")
    Although hydrophobia can refer to a general fear of water, a strong aversion to drinking water is also a typical symptom of rabies.
  9. hydrologic
    relating to the branch of geology that studies Earth's water
    The Glossary of Meteorology defines “drought” as “a period of abnormally dry weather sufficiently prolonged for the lack of water to cause serious hydrologic imbalance in the affected area.” Los Angeles Times
  10. hydrotherapy
    the internal and external use of water in the treatment of disease
    The official name for it was hydrotherapy—the purpose was to keep the wounds clean and prevent infection. The 57 Bus
    hydor + therapeia ("curing")
  11. hydraulic
    moved or operated or effected by liquid
    Fracking—or hydraulic fracturing—is a technique in which water and chemicals are pumped into shale rock at high pressure to extract gas. BBC
    hydor + aulos ("musical instrument, pipe") + ic (suffix forming adjectives)
    Add an "s" to the end of the adjective, and this word becomes a noun that refers to the "study of the mechanics of fluids."
  12. hydroelectric
    of or relating to or used in the production of electricity by waterpower
    Unlike fossil fuels, wind, solar, and hydroelectric systems generate electricity with no associated air pollution emissions. 1919 The Year That Changed America
    hydor + elektron ("amber, pale gold") + ic (suffix forming adjectives)
    Electricity was first generated in the 17th century when a piece of amber was rubbed and used to attract other substances, which accounts for the link to the Greek root elektron.
  13. hydrodynamics
    study of fluids in motion
    He took the standard equations for hydrodynamics, which describe fluid flow in everything from tea kettles to oceans, and modified them to account for how individual particles use energy. Nature
    hydor + dynamis ("power") + ics (suffix forming names of sciences or disciplines)
  14. hydroponic
    of or relating to growing plants in water without soil
    So far, frosted food was brought from Earth in flying icicles; a few community gardens were greening up in hydroponic plants. The Martian Chronicles
  15. hydroponics
    a technique of growing plants in liquid without soil
    The farm at Luther Jackson uses aquaponics technology, combining the methods of hydroponics, growing plants with water rather than soil, and aquaculture, the process of growing and raising fish. Washington Post
    hydor + ponos ("labor") + ics (suffix forming names of sciences)
  16. hydroplane
    glide or skim over the surface of the water
    The “dynamics of the vehicles involved in the accident strongly indicate that the vehicles had much higher levels of traction than would be available in a hydroplaning situation.” A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age
    This word is formed by combining the root hydr with the word airplane. As a noun, hydroplane refers to an aircraft that can take off and land on water.
  17. hydrogen
    a colorless, odorless gas; the lightest chemical element
    To a chemist, water is two atoms of hydrogen and one of oxygen. New York Times
    hydor + gen (suffix meaning "thing that produces or causes")
  18. hydrosphere
    the watery layer of the earth's surface
    The hydrosphere consists of all Earth’s fresh and salt water, including the water vapor and rain in the atmosphere and the water underground. Miller & Levine Biology
Created on Fri Aug 14 11:45:38 EDT 2015 (updated Fri May 12 11:05:08 EDT 2023)

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