n.
Pronunciation: ' b ī - ō - ˌ r ē -j ə n
Function: noun
Date: 1978
: a region whose limits are naturally defined by topographic and biological features (as mountain ranges and ecosystems)
– bio · re · gion · al \ ˌ b ī - ō - ' r ē j-n ə l, - ' r ē -j ə -n ə l \ adjective