: 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
The duo flew to the station in early June on the first crewed flight of the Boeing Starliner, but the spacecraft experienced helium leaks and thruster issues in transit.
—
Sara Hashemi, Smithsonian Magazine, 31 Jan. 2025
However, a series of technical problems—including helium leaks and thruster failures—forced NASA and Boeing to return the capsule to Earth without a crew in September 2024.
—Jonathan Granoff, Newsweek, 29 Jan. 2025
After Starliner arrived at the space station, NASA and Boeing worked for weeks to better understand the problems — including helium leaks and propulsion issues — that plagued the first leg of the test mission.
—Jackie Wattles, CNN, 28 Jan. 2025
But there was enough helium to keep the Pilgrim aloft—for its first official flight, to mark Akron’s centennial in July 1925, and for the debut of the Santa Claus Express, which rained gifts down on the city that December.
—April White, JSTOR Daily, 20 Jan. 2025
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Sara Hashemi, Smithsonian Magazine, 31 Jan. 2025
However, a series of technical problems—including helium leaks and thruster failures—forced NASA and Boeing to return the capsule to Earth without a crew in September 2024.
—Jonathan Granoff, Newsweek, 29 Jan. 2025
After Starliner arrived at the space station, NASA and Boeing worked for weeks to better understand the problems — including helium leaks and propulsion issues — that plagued the first leg of the test mission.
—Jackie Wattles, CNN, 28 Jan. 2025
But there was enough helium to keep the Pilgrim aloft—for its first official flight, to mark Akron’s centennial in July 1925, and for the debut of the Santa Claus Express, which rained gifts down on the city that December.
—April White, JSTOR Daily, 20 Jan. 2025
See all Example Sentences for helium
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Cite this Entry
“Helium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/helium. Accessed 7 Feb. 2025.
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Medical Definition
helium
noun
he·li·um
ˈhē-lē-əm 
: 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
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