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

This binary consists of a pre-main-sequence star that has gathered mass but hasn't yet triggered the fusion of hydrogen to helium in its core, and its companion, a red dwarf star. — Robert Lea, Space.com, 17 July 2026

Beyond this, next generation reactor technologies, several of which are being deployed, use coolants such as helium, molten salt, and liquid metal instead of water. — Scott Montgomery, Forbes.com, 17 July 2026

Cherubim had theorized that some small, rocky planets like LHS 1140 b could develop atmospheres with large amounts of helium over time. — Adam Kovac, Scientific American, 16 July 2026

According to Cherubim, the only atmospheric gas that has been robustly identified is helium. — Doyle Rice, USA Today, 16 July 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