Elements of the Universe: Hydor

The ancients believed that the universe, or the kosmos/cosmos, was composed of five basic elements: earth, air, fire, water, and sky. (When advances in technology revealed more elements that were much smaller, these classical five were reclassified as states of matter--solid, liquid, gas, and plasma.) The ancient words for these elements show up in our language today, through Greek and Latin roots for earth (terra, geo), water (hydor, aqua), fire (ignis, pyr), and words from the sky including air (aer, ventus, aither), star (astron), and sun (sol).

Find words from cosmos here, then check out lists from other Greek and Latin word-forming elements: cosmos, terra, geo, hydor, aqua, ignis, pyr, aer, ventus, aither, astron, sol

Activities for this list:

definitions & notes only words
  1. hydra
    trouble that cannot be overcome by a single effort because of its many aspects or its persistent and pervasive quality
    Right now, Nick Fury is believed dead and SHIELD, since revealed to be the face of HYDRA, was dismantled.The Verge (Apr 13, 2015)
    hydor (water)
    In the Marvel Universe, HYDRA is a criminal organization trying to take over the world. It got its name from a mythical sea serpent that Hercules had difficulty fighting, because when he cut off one head, two more took its place.
  2. hydrant
    a discharge pipe with a valve and spout at which water may be drawn from the mains of waterworks
    Every now and again, there were fire hydrants and mailboxes painted the colors of the flag.New York Times (Jul 14, 2014)
    hydor (water) + ant (suffix indicating an agent or instrument)
    Although fire hydrants can be painted for decorative or patriotic reasons, some colors are chosen as messages to firefighters about the condition of the pipe, the availability of water, or the strength of the flow.
  3. hydration
    the process of combining with water; usually reversible
    Good hydration improves cognitive function, and recommending water as the beverage of choice can help in the fight against childhood obesity.New York Times (Aug 18, 2015)
    hydor (water) + ation (suffix forming nouns of action)
    The definition makes hydration sound like a chemical process, but unlike hydrolysis, it is an addition of water that usually refreshes rather than decomposes.
  4. dehydrate
    lose water or moisture
    "If you're dehydrated, your heart has to work three to five times harder to pump blood because it gets thicker. And you get tired."Los Angeles Times (Mar 27, 2015)
    de (prefix meaning "down, off, away, from") + hydor (water) + ate (suffix forming verbs)
    As the example sentence shows, "dehydrated" has an unhealthy tone when it is used as a participial adjective to describe a live person. But for corpses and foods, a decision to dehydrate ("to preserve by removing all water and liquids") can result in museum-worthy mummies and a long-lasting store of emergency edibles.
  5. hydrophobia
    a symptom of rabies consisting of an aversion to liquids
    But before death there's hydrophobia — a fear of water — and transformation, with the human host resembling the diseased animal that passed the virus along.Seattle Times (Aug 8, 2012)
    hydor (water) + phobos (fear)
    Although a phobia is often seen as "an anxiety disorder characterized by irrational fear," one form of hydrophobia has a direct physical origin. The bite of a rabid animal transmits a virus that affects a person's ability to swallow. The hydrophobia develops because the thirsty person wants to drink the water but can't. In addition, the rabies virus eventually makes its way into the brain and causes the person to act in inhuman ways.
  6. hydrotherapy
    the internal and external use of water in the treatment of disease
    Also known as hydrotherapy, balneotherapy involves the use of water for therapeutic purposes, and it dates as far back as 1700 B.C.Washington Post (Apr 28, 2014)
    hydor (water) + therapeia (curing)
    The Latin "balneum" means "bath." A visitor to a Roman bathhouse often split his time among waters that were cold, warm, and hot. In addition to being a method of cleaning, the bathhouses were places to relax and socialize. As soothing as water can be, the medical benefits of hydrotherapy or balneotherapy have not been proven.
  7. 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 (Jun 15, 2015)
    hydor (water) + aulos (musical instrument, hollow tube) + ic (suffix forming adjectives)
    Add an "s" to the end of the adjective, and the word becomes a noun that refers to the "study of the mechanics of fluids." Hydraulics is similar to hydrodynamics, except that it is more concerned with practical applications, such as the designs of machines and dams.
  8. hydroelectric
    of or relating to or used in the production of electricity by waterpower
    Knowing the hydraulics of the dams and the biology, life-cycles and development of young fish, will allow better designs of hydroelectric dams.Forbes (Nov 4, 2014)
    hydor (water) + 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. This first experiment with a rare gemstone did not accomplish much. Nowadays, scientists are more focused on harnessing plentiful resources, such as water, in order to empower humanity.
  9. hydrodynamics
    study of fluids in motion
    I’m struck by the sharks’ brilliant hydrodynamics, their streamlined bodies.The Guardian (Jun 7, 2015)
    hydor (water) + dynamis (power) + ics (suffix forming names of sciences or disciplines)
    The opposite of hydrodynamics is hydrostatics. While hydrodynamics can explain how sharks move, hydrostatics can explain how boats float.
  10. hydroponics
    a technique of growing plants in liquid without soil
    The fish are what make the system "aquaponic," a particularly organic variant on traditional hydroponics.The Verge (Nov 18, 2014)
    hydor (water) + ponos (labor) + ics (suffix forming names of sciences or disciplines)
    In addition to hydroponics and aquaponics are aeroponics and fogponics. As the roots suggest, compared to the traditional growing of plants, these methods require more work to control the nutrients and environment. But this extra work enables plants to grow anywhere, including a space station.
  11. hydrofoil
    a speedboat that is equipped with winglike structures that lift it so that it skims the water at high speeds
    Fast hydrofoils and slow, car-ferrying ships go back and forth between the islands daily.Washington Post
    hydor (water) + folium (leaf)
    A hydrofoil can be the same as a hydroplane. But a hydroplane can also be a seaplane that can land on or take off from water; and a hydroplaning car is sliding uncontrollably on a wet road. Hydrofoils are expensive to build and maintain, and their sharp wings are dangerous to marine animals, so the vessel and the word are slowly going out of use.
  12. hydrogen
    a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe
    To a chemist, water is two atoms of hydrogen and one of oxygen.New York Times (Jul 24, 2015)
    hydor (water) + gen (suffix meaning "thing that produces or causes")
    Here are additional facts about hydrogen that a chemist would know:
    1) its monatomic form is the most abundant chemical element in the universe (found in stars)
    2) its diatomic form is the third most abundant element on Earth (found in water or hydrocarbons such as octane or coal)
    3) it is highly flammable.

Sign up, it's free!

Whether you're a student, an educator, or a lifelong learner, Vocabulary.com can put you on the path to systematic vocabulary improvement.