helium

noun

he·​li·​um ˈhē-lē-əm 

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

While there are no modular reactors up and running yet in the United States, Albrecht said some of those in the design phase will use molten salt, helium or liquid metal to help cool the fission process, obviating the need for large amounts of water. —John Aguilar, Denver Post, 7 May 2026

The students, along with others from Country Day’s lower school, gathered on the campus football field May 5 to watch the balloon get filled with helium and lift into the sky. —Noah Lyons, San Diego Union-Tribune, 7 May 2026

Officials said there were a lot of flammable materials inside, including foam, fabric, helium tanks and cardboard. —Elijah Westbrook, CBS News, 6 May 2026

In normal times, Qatar produces a third of the world’s helium but has shuttered its gas industry. —Dominic Dudley, semafor.com, 4 May 2026

Word History

Etymology

New Latin, from Greek hēlios

First Known Use

1871, in the meaning defined above

Rhymes for helium

• cilium

Kids Definition

helium

noun

he·​li·​um ˈhē-lē-əm 

: 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 

: 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