HELIUM
helium, He, atomic number
(noun) a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)
Source: WordNet® 3.1
Etymology
Noun
helium (countable and uncountable, plural heliums)
(uncountable) The second lightest chemical element (symbol He) with an atomic number of 2 and atomic weight of 4.002602, a colorless, odorless and inert noble gas.
(countable) A form or sample of the element.
Synonyms
• E939 when used as a packaging gas
Source: Wiktionary
He"li*um, n. Etym: [NL., fr. Gr. (Chem.)
Definition: A gaseous element found in the atmospheres of the sun and earth
and in some rare minerals.
Source: Webster’s Unabridged Dictionary 1913 Edition