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hydro-

1 American  
  1. a combining form representing hydrogen in compound words, denoting especially a combination of hydrogen with some negative element or radical.

    hydrobromic.


hydro- 2 American  
  1. a combining form meaning “water,” used in the formation of compound words.

    hydroplane; hydrogen.


hydro 3 American  
[hahy-droh] / ˈhaɪ droʊ /

noun

plural

hydros
  1. Informal. hydroelectric power.

  2. Informal. hydroplane.

  3. British.

    1. a bathhouse, hotel, or resort catering to people taking mineral-water health cures; spa.

    2. an establishment furnishing hydrotherapy.


adjective

  1. Informal. of, relating to, or furnishing water, water power, or hydroelectricity.

    funds for new hydro projects.

Hydro 1 British  
/ ˈhaɪdrəʊ /

noun

  1. (esp in Canada) a hydroelectric power company or board

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

hydro 2 British  
/ ˈhaɪdrəʊ /

noun

  1. (esp formerly) a hotel or resort, often near a spa, offering facilities for hydropathic treatment

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

hydro 3 British  
/ ˈhaɪdrəʊ /

adjective

  1. short for hydroelectric

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

noun

  1. a Canadian name for electricity when it is supplied to a residence, business, institution, etc

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
hydro- 4 British  

combining form

  1. indicating or denoting water, liquid, or fluid

    hydrolysis

    hydrodynamics

  2. indicating the presence of hydrogen in a chemical compound

    hydrochloric acid

  3. indicating a hydroid

    hydrozoan

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

hydro– Scientific  
  1. A prefix that means: “water” (as in hydroelectric) or “hydrogen,” (as in hydrochloride).


Usage

What does hydro- mean? Hydro- is a combining form used like a prefix that has two distinct senses.The first of these senses is “water,” and this form of hydro- is often used in a variety of scientific and technical terms. Hydro- comes from Greek hýdōr, meaning “water.”The second of these senses is “hydrogen,” and this form of hydro- is occasionally used in a variety of scientific terms, especially in chemistry. Hydrogen, the lightest of the elements, combines with oxygen to form water. The word hydrogen comes from French hydrogène. The suffix -gen, or its equivalent in French, means "that which produces." Hydrogen literally translates to "that which produces water."What are variants of hydro-?When combined with words or word elements that begin with a vowel, hydro- becomes hydr-, as in hydrant. Want to know more? Read our Words That Use article on hydr-.

Etymology

Origin of hydro-1

< Greek, combining form of hýdōr water

Origin of hydro1

1880–85; by shortening of compounds with hydro- 1 ( -o ); hydro ( def. 4 ) hydro- 1 analyzed as an adj.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

In the pitch black of the mine, mud-splattered men with headlamps drill into the rock in two-man teams, using hydro drills with long, thin nozzles that shoot out pressurized water to loosen the ore.

From The Wall Street Journal

"With the melting ice, you get the potential for hydro power in the area where the land is being exposed… so this presents itself as an interesting prospect."

From BBC

Ecuador, a country of 17 million, relies on hydro generation for 70 percent of its electric power.

From Barron's

Slovakia's high rate of low-carbon energy generation, from hydro to nuclear, and growing use of renewables, also means that the country's electric cars are eligible for larger levels of government discounts when customers buy them, such as the UK's Electric Car Grant.

From BBC

They do not include smaller-scale gas, biomass and hydro operators feeding in electricity at a local level, but these contribute a relatively small fraction of Britain's total generation.

From BBC