airstream vs jet stream

airstream and jet stream both are nouns.

Word	Noun	Adjective	Verb	Adverb
airstream	Yes	No	No	No
jet stream	Yes	No	No	No

As nouns, jet stream is a hyponym of airstream; that is, jet stream is a word with a more specific, narrower meaning than airstream:

airstream: a relatively well-defined prevailing wind
jet stream: a high-speed high-altitude airstream blowing from west to east near the top of the troposphere; has important effects of the formation of weather fronts

airstream (noun)	jet stream (noun)
a relatively well-defined prevailing wind	a high-speed high-altitude airstream blowing from west to east near the top of the troposphere; has important effects of the formation of weather fronts
the flow of air that is driven backwards by an aircraft propeller