Something that affords pleasure, diversion, or amusement: a clown at a birthday party, a Broadway show, your friends fighting over the last potato chip. From the Old French entretenir, a word related to hospitality: to entertain guests or occupy with pleasure.
Entertainment evolves over time. Activities that were once part of hunting or war become spectator sports; activities used for child rearing or social interaction develop into games for kids; activities for sedentary people develop into virtual recreations on television or tablet computers. Entertainment is a very human activity that hits on themes that the brain was evolved to deeply react to, such as murders and backstabbing. It is also a highly adaptable medium, enabling it to be scaled from private enjoyment to global audiences.