firework vs low explosive

firework and low explosive both are nouns.

Word	Noun	Adjective	Verb	Adverb
firework	Yes	No	No	No
low explosive	Yes	No	No	No

As nouns, low explosive is a hypernym of firework; that is, low explosive is a word with a broader meaning than firework:

firework: (usually plural) a device with an explosive that burns at a low rate and with colored flames; can be used to illuminate areas or send signals etc.
low explosive: an explosive with a low rate of combustion

firework (noun)	low explosive (noun)
(usually plural) a device with an explosive that burns at a low rate and with colored flames; can be used to illuminate areas or send signals etc.	an explosive with a low rate of combustion