ar

(noun) a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere. Synonyms: argon, Ar, atomic number 18.

(noun) a unit of surface area equal to 100 square meters. Synonyms: are.

(noun) a state in south central United States; one of the Confederate states during the American Civil War. Synonyms: Arkansas, Land of Opportunity, AR.