fundamental measure vs quantity

fundamental measure and quantity both are nouns.

Word	Noun	Adjective	Verb	Adverb
fundamental measure	Yes	No	No	No
quantity	Yes	No	No	No

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

fundamental measure: one of the four quantities that are the basis of systems of measurement
quantity: how much there is or how many there are of something that you can quantify

Other hypernyms of fundamental measure include amount, measure.

fundamental measure (noun)	quantity (noun)
one of the four quantities that are the basis of systems of measurement	how much there is or how many there are of something that you can quantify
	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