What is entertainment for one person or group may be considered work by another. Entertaiment is a broad category and it covers many forms of art. It is not easy to define and that is part of its appeal. Many of the familiar forms of entertaiment have crossed over different media and they have demonstrated a longevity.
Getting back to the origins of the word entertaintaiment, it has roots in Greek through the word enteron. It also has connections to the Medieval Latin intertenere which means “to hold inside.” The prefix inter means inside and tenere means to stretch or extend. This fits well with the elongated time it takes for humans to readjust to a phase shift. Cockroaches and sparrows readjust in 4 days and rats take 8 days.