Something affording pleasure or diversion; an agreeable occupation for the mind; a diverting performance or spectacle: a theater show. There are many other forms of entertainment, however, and what may appear to be mere amusement may also be a method of attaining perception or highbrow growth. (See the Notes section below for examples.) In short, entertainment is a kind of leisure activity that hits on the themes the human brain was shaped to react deeply to in order to understand the world around us.
You will sometimes see the word entertainment abbreviated to entmt. on fliers or in industry news publications where space is at a premium. But this abbreviation is rare in general use.