Entertaiment is a genre that uses storytelling to engage with people. It often involves an emotional connection to the story that creates a sense of euphoria. Examples of entertainment include music, art and films. One famous example is Scheherazade, a Persian professional storytelling tradition that inspired Rimsky-Korsakov to write an orchestral piece, director Pasolini to make a film adaptation, and an innovative video game.
Sometimes the word entertainment is abbreviated to entmt on fliers or in industry news publications where space is limited. It is rarely abbreviated in general prose, though you may see it on a concert flier or in short hand note taking.