Meaning

noun a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere

noun a unit of surface area equal to 100 square meters

noun a state in south central United States; one of the Confederate states during the American Civil War

originFrom Middle English *ar, arres pl, from earlier *er.

Etymology from Wiktionary, CC BY-SA 3.0