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

Fusion energy is the process of forcing two hydrogen atoms to combine and form one helium atom, which releases huge amounts of power. —Diana Olick, CNBC, 21 May 2025

This showed that changes in the truck's speed produced turbulence in the liquid helium, making measurements of its presence unreliable. —John Timmer, ArsTechnica, 19 May 2025

Scientists believe lighter elements such as hydrogen and helium, and even a small amount of lithium, likely existed early on after the big bang created the universe 13.8 billion years ago. —Ashley Strickland, CNN Money, 3 May 2025

After that event, there was plenty of hydrogen and helium, as well as a dash of lithium. —Paul Smaglik, Discover Magazine, 1 May 2025

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