1. ecology an assemblage of plants and animals living together and occupying a given area —note 1. with plants, a closed community has components that are so completely utilizing the site that they exclude (or give the appearance of excluding) further entrants —note 2. classifying a community as closed is subjective and usually based on one-time measurements or observations —see nodum 2. societal an urban or rural group of human families, as in towns, etc. This definition last updated 10/25/2008