hydrogen

noun

hy·​dro·​gen ˈhī-drə-jən 

-dər-

: a nonmetallic gaseous chemical element with atomic number 1 that is the simplest and lightest of the elements and that is used especially in the processing of fossil fuels and the synthesis of ammonia

—often used before another noun

hydrogen gas

hydrogen atoms

a hydrogen vehicle

the hydrogen industry

see Chemical Elements Table compare deuterium, tritium

hydrogenous

hī-ˈdrä-jə-nəs 

adjective

Examples of hydrogen in a Sentence

Recent Examples on the Web

But despite its significant defense manufacturing presence, the South Korean company has gone beyond what its former name of Korea Explosives Group suggests, moving further into the renewable energy industry through solar and wind farms and clean hydrogen technology. —Chad De Guzman, TIME, 30 May 2024

Pricey hydrogen But much of Aramco’s other whizzbang technology is still too expensive to market. —Vivienne Walt, Fortune, 23 May 2024

Liquid hydrogen is another popular fuel option that has long been used in both public and private space launches, from the iconic Apollo 11 mission that took a man to the moon in 1969 to NASA’s recent Artemis mission. —Lily Carey, Discover Magazine, 22 May 2024

That’s because the water jet contained molecular hydrogen. —Popular Science Staff, Popular Science, 22 May 2024

Word History

Etymology

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

First Known Use

1788, in the meaning defined above

Phrases Containing hydrogen

• heavy hydrogen
• hydrogen bomb
• hydrogen bond
• hydrogen bromide
• hydrogen chloride
• hydrogen cyanide
• hydrogen fluoride
• hydrogen iodide
• hydrogen ion
• hydrogen peroxide
• hydrogen sulfide

Kids Definition

hydrogen

noun

hy·​dro·​gen ˈhī-drə-jən 

: a chemical element that is the simplest and lightest of all chemical elements and is normally found alone as a colorless odorless highly flammable gas having two atoms per molecule see element

hydrogenous

hī-ˈdräj-ə-nəs 

adjective

Etymology

from French hydrogène "hydrogen," from hydr- "water" and -gène "producer"; so called because when hydrogen gas burns, it combines with oxygen to produce water

Medical Definition

hydrogen

noun

hy·​dro·​gen ˈhī-drə-jən 

: 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

hydrogenous

hī-ˈdräj-ə-nəs 

adjective