Medium  —n. (pl. Media or -s) 1 middle quality, degree, etc. Between extremes (find a happy medium). 2 means of communication (medium of television). 3 substance, e.g. Air, through which sense-impressions are conveyed. 4 physical environment etc. Of a living organism. 5 means. 6 material or form used by an artist, composer, etc. 7 liquid (e.g. Oil or gel) used for diluting paints. 8 (pl. -s) person claiming to communicate with the dead. —adj. 1 between two qualities, degrees, etc. 2 average (of medium height). [latin medius middle]