airstream vs backwash

airstream and backwash both are nouns.

Word	Noun	Adjective	Verb	Adverb
airstream	Yes	No	No	No
backwash	Yes	No	No	No

As nouns, airstream and backwash are synonyms defined as:

airstream and backwash: the flow of air that is driven backwards by an aircraft propeller

Other synonyms of airstream include race, slipstream, wash.

airstream (noun)	backwash (noun)
a relatively well-defined prevailing wind	the wave that spreads behind a boat as it moves forward
the flow of air that is driven backwards by an aircraft propeller	the flow of air that is driven backwards by an aircraft propeller
	the consequences of an event (especially a catastrophic event)