argon

noun

Etymology: Etymology tree Proto-Indo-European *né Proto-Indo-European *n̥- Proto-Hellenic *ə- Ancient Greek ᾰ̓- (ă-) Proto-Indo-European *werǵ- Proto-Indo-European *-om Proto-Indo-European *wérǵom Proto-Hellenic *wérgon Ancient Greek ἔργον (érgon) Proto-Indo-European *-ós Proto-Hellenic *-ós ▲ Ancient Greek -ος (-os)influ. Ancient Greek -ός (-ós) Ancient Greek ᾱ̓ργός (ārgós) Proto-Indo-European *kerh₃-der.? Latin carbōlbor. French carbonebor. English carbonbf. English -on English argon From Ancient Greek ἀργός (argós, “idle, lazy”), because of its inertness, + -on, used for all noble gases.

1. The chemical element (symbol Ar) with an atomic number of 18. The third most abundant gas in the Earth's atmosphere, it is a colourless, odourless, inert noble gas.
2. An atom of this element.