quantum vs quantity

quantum and quantity both are nouns.

Word	Noun	Adjective	Verb	Adverb
quantum	Yes	No	No	No
quantity	Yes	No	No	No

As nouns, quantity is a hypernym of quantum; that is, quantity is a word with a broader meaning than quantum:

quantum: (physics) the smallest discrete quantity of some physical property that a system can possess (according to quantum theory)
quantity: how much there is or how many there are of something that you can quantify

Other hypernyms of quantum include amount, measure.

As nouns, quantity is a hypernym of quantum; that is, quantity is a word with a broader meaning than quantum:

quantum: a discrete amount of something that is analogous to the quantities in quantum theory
quantity: the concept that something has a magnitude and can be represented in mathematical expressions by a constant or a variable

quantum (noun)	quantity (noun)
(physics) the smallest discrete quantity of some physical property that a system can possess (according to quantum theory)	how much there is or how many there are of something that you can quantify
a discrete amount of something that is analogous to the quantities in quantum theory	an adequate or large amount
	the concept that something has a magnitude and can be represented in mathematical expressions by a constant or a variable