Something that provides pleasure, amusement or distraction. People might find entertainment in a performance, reading a book or even doing a crossword puzzle. They might also consider playing sports or games a form of entertainment.
Sometimes entertainment hits on the points that the human mind was evolved to deeply react to, such as social backstabbing and murder. A good example is the story of Scheherazade, a character from Persian professional storytelling traditions. The power of the tale has led to retellings in other media such as music, film and video game. Rimsky-Korsakov, Ravel and Szymanowski wrote orchestral works based on the story; Pasolini made a film; and innovative new games have been inspired by the tale. The connections between different forms of entertainment are clear.