helium

noun

he·​li·​um ˈhē-lē-əm How to pronounce helium (audio)
ˈhēl-yəm
: a chemical element of the noble gas group with atomic number 2 that is found especially in natural gases and used chiefly for inflating airships and balloons, as a coolant for superconductors, and as a component of inert atmospheres (as in welding)
—often used before another noun
helium balloons
helium gas
 see Chemical Elements Table

Examples of helium in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
These deviations are due to the interaction between the helium in their atmosphere and traces of other elements, which vary between white dwarfs, depending on what material has interacted with the star over the course of its lifetime. — Jack Guy, CNN Money, 16 Oct. 2026 Cooler white dwarfs with mixed hydrogen and helium atmospheres often would glow cyan or pale blue, caused as hydrogen molecules collide with helium atoms in their dense atmospheres. — Robert Lea, Space.com, 15 Oct. 2026 This cyan-pale blue is caused by hydrogen molecules colliding with helium atoms inside their ultra-dense atmospheres. — Laura Baisas, Popular Science, 15 Oct. 2026 Metals built for extreme environments To witness this microscopic change in real time, researchers cooled metal samples to -253°C using gaseous helium at the ISIS Neutron and Muon Source in Oxfordshire. — Mrigakshi Dixit, Interesting Engineering, 14 Oct. 2026 See All Example Sentences for helium

Word History

Etymology

New Latin, from Greek hēlios

First Known Use

1871, in the meaning defined above

Time Traveler
The first known use of helium was in 1871

Rhymes for helium

See All Rhymes for helium

Browse Nearby Words

Helisoma
helium
helium-3
See all Nearby Words

Cite this Entry

“Helium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/helium. Accessed 20 Oct. 2026.

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Kids Definition

helium

noun
he·​li·​um ˈhē-lē-əm How to pronounce helium (audio)
: a light colorless nonflammable element that is found in various natural gases and is used especially to blow up balloons see element

Medical Definition

helium

noun
he·​li·​um ˈhē-lē-əm How to pronounce helium (audio)
: a light colorless nonflammable gaseous element found especially in natural gases and used chiefly for inflating airships and balloons, for filling incandescent lamps, and for cryogenic research
—symbol He see Chemical Elements Table

More from Merriam-Webster on helium

Britannica.com: Encyclopedia article about helium

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