Wordnet 3.0
NOUN (1)
1.
a major biotic community characterized by the dominant forms of plant life and the prevailing climate;
The Collaborative International Dictionary of English v.0.48:
Biome \Bi"ome\ (b[imac]"[=o]m), n. [Gr. bi`os life.]
1. (Ecology) a specific type of complex ecological community
characterized by specific environmental conditions and a
distinctive group of plants and animals, maintained in a
relatively stable equilibrium, such as a rain forest
biome or prairie biome.
[PJC]
2. a particular region which is a biome[1].
[PJC]
WordNet (r) 3.0 (2006):
biome
n 1: a major biotic community characterized by the dominant
forms of plant life and the prevailing climate