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

The sound of children playing has given way to the rattle of helium balloons clinging to the memorial for 11-year-old QueenEr’Re Reed. —Cameron Knight, Cincinnati Enquirer, 8 Mar. 2026

This is because, despite forming like stars from collapsing patches of overdense and cool gas, brown dwarfs fail to gather the mass needed to generate the temperatures and pressures in their cores needed to fuse hydrogen to helium. —Robert Lea, Space.com, 6 Mar. 2026

Weston told him about his idea for designing a device to detect a helium leak, should there ever be one. —IEEE Spectrum, 5 Mar. 2026

The helium flow problem was caused by a faulty seal in the quick-disconnect for the tubing. —Jon Martindale, PC Magazine, 4 Mar. 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