hydrogen

noun hy·dro·gen \ ˈhī-drə-jən , -dər- \

|Updated on: 19 Jun 2018

Definition of hydrogen

: a nonmetallic element that is the simplest and lightest of the elements, is normally a colorless odorless highly flammable diatomic gas, and is used especially in synthesis — see Chemical Elements Table — compare deuterium, tritium

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hydrogenous

play \hī-ˈdrä-jə-nəs\ adjective

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See hydrogen defined for kids

Recent Examples of hydrogen from the Web

Those are people who have skills in cybersecurity, machine learning — a subset of artificial intelligence engineering — and anything to do with automated and electric vehicle systems such as battery technology, fuel cell systems and hydrogen.

— jamie l. lareau, Detroit Free Press, "In auto talent war, GM hires 9,000, spends $1 billion on offices," 14 June 2018
Carbon Engineering, a Canadian company, is already making a liquid fuel by sucking carbon dioxide (CO2) out of the atmosphere and combining it with hydrogen from water.

— National Geographic, "This Gasoline Is Made of Carbon Sucked From the Air," 7 June 2018
Typically, researchers can measure how quickly a star orbits by looking at the spectrum of light emitted by the hydrogen inside the star.

— avery thompson, Popular Mechanics, "The Largest Neutron Star Ever, Found With a Clever New Technique," 30 May 2018
The x-rays produced by an AGN ionize clouds of hydrogen gas in the galactic bulge around it, setting them aglow at particular frequencies that produce distinct peaks in the galaxy’s spectrum.

— daniel clery, Science | AAAS, "Discovery of middleweight black holes could explain origin of million-solar-mass monster," 30 May 2018
If the forces that hold atoms together were even a bit different, the atomic reactions that power the stars wouldn’t work, and our cosmos would consist of nothing but hydrogen.

— NBC News, "Could alien life exist in parallel universes?," 28 May 2018
The last, conducted in September, was widely considered to have been a hydrogen explosion.

— anna fifield, Anchorage Daily News, "North Korea declares its nuclear test site closed after a ‘huge explosion’," 24 May 2018
The extremely light hydrogen escaped Venus’s gravity, and the oxygen was consumed by rusting into the rocks.

— scott denning, Washington Post, "May the 4th be with Earth, a perfect planet that’s not too Hoth or Tatooine," 4 May 2018
The new findings revealed that a large fraction of the hydrogen in the immediate vicinity of the newfound quasar was neutrally charged.

— charles q. choi, Scientific American, "Oldest Supermassive Black Hole Found from Universe’s Infancy," 6 Dec. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'hydrogen.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of hydrogen

French hydrogène, from hydr- + -gène -gen; from the fact that water is generated by its combustion

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First Known Use: 1788

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HYDROGEN Defined for English Language Learners

hydrogen

noun

Definition of hydrogen for English Language Learners

: a chemical element that has no color or smell and that is the simplest, lightest, and most common element

HYDROGEN Defined for Kids

hydrogen

noun hy·dro·gen \ ˈhī-drə-jən \

Definition of hydrogen for Students

: a colorless, odorless, and tasteless flammable gas that is the lightest of the chemical elements

History for hydrogen

When hydrogen is burned it combines with oxygen to make water. That fact accounts for the name of this gas. The word hydrogen was formed from two Greek roots. The first, hydro-, means “water,” and the second, -gen, means “giving rise to, producing.”

Medical Dictionary

hydrogen

noun hy·dro·gen \ ˈhī-drə-jən \

medical Definition of hydrogen

: a nonmetallic element that is the simplest and lightest of the elements and that is normally a colorless odorless highly flammable diatomic gas —symbol H — see deuterium, tritium — Chemical Elements Table

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