boom box vs stereo system

boom box and stereo system both are nouns.

Word	Noun	Adjective	Verb	Adverb
boom box	Yes	No	No	No
stereo system	Yes	No	No	No

As nouns, stereo system is a hypernym of boom box; that is, stereo system is a word with a broader meaning than boom box:

boom box: a portable stereo
stereo system: reproducer in which two microphones feed two or more loudspeakers to give a three-dimensional effect to the sound

Other hypernyms of boom box include stereo, stereophonic system, stereophony.

boom box (noun)	stereo system (noun)
a portable stereo	reproducer in which two microphones feed two or more loudspeakers to give a three-dimensional effect to the sound