... part of George North's and Teacher Explorer Center's Web site at UNO Media An ancient country of southwest Asia in present-day northwest Iran. Settled by an Indo-European people, it became part of the Assyrian Empire and was conquered c. 550 B.C. by Cyrus the Great, who added it to the Persian Empire. Something, such as an intermediate course of action, that occupies a position or represents a condition midway between extremes. An intervening substance through which something else is transmitted or carried on. An agency by which something is accomplished, conveyed, or transferred: The train was the usual medium of transportation in those days. pl. media. Usage Problem. a. A means of mass communication, such as newpapers, magazines, radio, or television. b. media. (used with a sing. or pl. verb). The group of journalists and others who constitute the communications industry and profession. pl. mediums. A person thought to have the power to communicate with the spirits of the dead or with agents of another world or dimension. Also called psychic. pl. media.a. A surrounding environment in which something functions and thrives. b. The substance in which a specific organism lives and thrives. c. A culture medium. A specific kind of artistic technique or means of expression as determined by the materials used or the creative methods involved: the medium of lithography. b. The materials used in a specific artistic technique: oils as a medium. A solvent with which paint is thinned to the proper consistency. Chemistry. A filtering substance, such as filter paper. A size of paper, usually 18 x 23 inches or 17 1/2 x 22 inches.