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

Rising fuel costs are upending travel and logistics, while tight supplies of other materials from the Middle East, such as fertilizer and helium, could lead to more expensive food and electronics. —Stephanie Yang, CNN Money, 4 Apr. 2026

Cosmic rays are a mix of different subatomic particles, including helium nuclei (two protons and two neutrons bound together) or even heavier elements. —Phil Plait, Scientific American, 3 Apr. 2026

That's pushed up not only oil prices, but the cost of fertilizer and other key commodities such as helium . —Sarah Min, CNBC, 3 Apr. 2026

Howard Hu, the program manager for Orion, said NASA was tracking an issue with the helium system that pressurizes Orion’s service module propulsion system to deliver fuel and oxidizer to the engine. —Eric Berger, ArsTechnica, 3 Apr. 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