Article about Entertaiment:

Entertainment is an agreed and agreeable occupation for the mind, or diversion and amusement. Entertainment is also an elaborate performance of one kind or another that is offered for the pleasure or enjoyment of guests or of the public at large. Many familiar forms of entertainment may serve a serious purpose, such as a ceremony, celebration, religious festival, or satire for example. The word entertain combines the root of the words enter, penetrate, and probe, all of which mean to go or force a way in:

Using Your Words: A Guide To Proper English Usage

By Mark Hamilton, Ph.D.