ep- Noun (plural eps)(informal) episode (of a TV serial, etc.) Origin Shortening.Initialism (plural EPs)Initialism of European Parliament.(automotive) Initialism of Extreme Pressure (an indicator used in lubricant additives.)(music) Initialism of Extended play (a vinyl record (recording on other media, such as a CD) that is shorter than an LP but longer than a single.) ep- - Computer Definition