n a means or instrumentality for storing or communicating information n the surrounding environment n an intervening substance through which signals can travel as a means for communication n (bacteriology) a nutrient substance (solid or liquid) that is used to cultivate micro-organisms n a liquid with which pigment is mixed by a painter n (biology) a substance in which specimens are preserved or displayed n an intervening substance through which something is achieved n a state that is intermediate between extremes; a middle position n someone who serves as an intermediary between the living and the dead n (usually plural) transmissions that are disseminated widely to the public n an occupation for which you are especially well suited