microcosmos
/ˌmaɪkrəˈkɑzmoʊs/
noun
- A small, self-contained world or system; a microcosm.
- The terrarium is a microcosmos where plants and insects thrive together.
- The aquarium was a microcosmos of ocean life, complete with coral and small fish.
- In the novel, the isolated island becomes a microcosmos of human society.