helium

noun he·li·um \ ˈhē-lē-əm , ˈhēl-yəm \

|Updated on: 18 Aug 2018

Definition of helium

: a light colorless inert gaseous element found especially in natural gases and used chiefly for inflating airships and balloons, in lamps, in cryogenic research, and as a component of inert atmospheres (as in welding) — see Chemical Elements Table

See helium defined for English-language learners

See helium defined for kids

Recent Examples of helium from the Web

An investigation of Abrahamson’s computer and phone revealed receipts and emails for weather balloons, helium tanks and rubber bands.

— tonya alanez, Sun-Sentinel.com, "Murder was elaborately staged suicide, police say," 13 July 2018
Within ten days of speaking with Harris, the 81-year-old Smith was found dead in a hotel room, with a bag over his head attached with rubber bands and two helium tanks.

— jonathan chait, Daily Intelligencer, "Will Trump Be Meeting With His Counterpart — Or His Handler?," 8 July 2018
One of the most significant changes is the use of stronger high-pressure helium tanks, known as composite overwrapped pressure vessels, or COPVs, that are submerged in the rocket's liquid oxygen propellant tanks.

— william harwood, CBS News, "SpaceX set to launch its first "block 5" Falcon 9 rocket," 10 May 2018
There’s a hissing noise, and the helium starts flowing.

— alex davies, WIRED, "Inside X, the Moonshot Factory Racing to Build the Next Google," 11 July 2018
Rides on a new helium observation balloon that is planned for the island will cost $39 to $99 for adults.

— gene sloan, USA TODAY, "Royal Caribbean unveils price list for revamped private island Perfect Day at CocoCay," 14 June 2018
Blue and gold helium balloons battled the wind along the property’s immaculate walkways.

— beth spotswood, San Francisco Chronicle, "SF’s grand old man of fly-fishing in Golden Gate Park," 16 May 2018
The helium is used to pressurize the propellant tanks and provide the muscle needed for steering.

— william harwood, CBS News, "SpaceX set to launch its first "block 5" Falcon 9 rocket," 10 May 2018
Sadiq Khan gave permission for the balloon, which was inflated with helium early Friday and will float over the Houses of Parliament during the demonstrations.

— alastair jamieson /, NBC News, "Sadiq Khan defends 'Trump baby' blimp, cites freedom to protest," 13 July 2018

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

Origin and Etymology of helium

New Latin, from Greek hēlios

NEW! Time Traveler

First Known Use: 1871

in the meaning defined above

See Words from the same year

HELIUM Defined for English Language Learners

helium

noun

Definition of helium for English Language Learners

: a chemical element that is a colorless gas, that is lighter than air, and that is often used to fill balloons

HELIUM Defined for Kids

helium

noun he·li·um \ ˈhē-lē-əm \

Definition of helium for Students

: a very light gaseous chemical element that is found in various natural gases, will not burn, and is used in balloons

Medical Dictionary

helium

noun he·li·um \ ˈhē-lē-əm \

medical Definition of helium

: 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