retention basin vs basin

retention basin and basin both are nouns.

Word	Noun	Adjective	Verb	Adverb
retention basin	Yes	No	No	No
basin	Yes	No	No	No

As nouns, basin is a hypernym of retention basin; that is, basin is a word with a broader meaning than retention basin:

retention basin: a storage site similar to a detention basin but the water in storage is permanently obstructed from flowing downstream
basin: the entire geographical area drained by a river and its tributaries; an area characterized by all runoff being conveyed to the same outlet

Other hypernyms of retention basin include catchment area, catchment basin, drainage area, drainage basin, river basin, watershed.

retention basin (noun)	basin (noun)
a storage site similar to a detention basin but the water in storage is permanently obstructed from flowing downstream	a bowl-shaped vessel; usually used for holding food or liquids
	a bathroom sink that is permanently installed and connected to a water supply and drainpipe; where you can wash your hands and face
	the entire geographical area drained by a river and its tributaries; an area characterized by all runoff being conveyed to the same outlet
	a natural depression in the surface of the land often with a lake at the bottom of it
	the quantity that a basin will hold