definite quantity vs quantity

definite quantity and quantity both are nouns.

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

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

definite quantity: a specific measure of amount
quantity: how much there is or how many there are of something that you can quantify

Other hypernyms of definite quantity include amount, measure.

definite quantity (noun)	quantity (noun)
a specific measure of amount	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