1. An area of land where all water drains to a common outlet, such as a river or lake; the drainage basin of a river system
The Amazon river basin is the largest in the world.
A bacia hidrográfica do Amazonas é a maior do mundo.
2. The region drained by a river and its tributaries
The Mississippi river basin covers much of central North America.
A bacia hidrográfica do Mississípi cobre grande parte da América do Norte central.