A basin is a landform. It is where an area of the earth dips on all sides towards the center. It looks like a bowl made out of the earth. It can be a closed or mostly closed area of water. It can be large or small.
You might find a basin on the floor of the ocean. A river can drain into a basin. A basin can exist without any water in it at all.
There are different kinds of basins. An area of land that dips and water falls into it is called a drainage basin. A low area of land with no outlet is called an Endorheic basin.
Merriam Webster (2011). Basin. Retrieved from http://mw1.merriam-webster.com/medical/basin?show=0&t=1296011979
Nussbaum, Greg. (2008). Mr. Nussbaum.com World Landforms. Retrieved from http://www.mrnussbaum.com/wlandforms.htm
APA Style: Basin. (2011, March). Retrieved from Facts4Me at https://www.facts4me.com
MLA Style: "Basin." Facts4Me. Mar. 2011. https://www.facts4me.com.