Noun, pl. biomes
1. A large naturally occurring community of flora and fauna occupying a major habitat. (Google Dictionary)
2. Climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. (wikipedia.org)
3. Any major regional biological community such as that of forest or desert. (wiktionary.org)
4. A major ecological community of organisms adapted to a particular climatic or environmental condition on a large geographic area in which they occur. (biology-online.org)
Word origin: bi: variant of bio-, esp. before a vowel + -ome: New Latin -ōma, -ōmat.