Entertaiment is an activity involving entertainment of all sorts. It can include such things as watching television or films, playing video games, attending music and dance performances, or creating or appreciating visual art. It also can involve reading books and poetry, playing sports or engaging in other recreational activities.
The word comes from medieval Latin intertenere, from the prefix inter- “inside” (like intranet) and the suffix tenere, from the Indo-European root ten, meaning to stretch or hold. It entered English around 15c.
The suffix -ment has come to mean “the result, effect” or “something that causes satisfaction.” It is used with verb stems in English ending in er or ir, for example amazement, betterment, and merriment. The suffix is also used with nouns, for instance in satire and in ceremonies and celebrations such as religious festivals.