constant quantity vs quantity

constant quantity and quantity both are nouns.

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

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

constant quantity: a quantity that does not vary
quantity: the concept that something has a magnitude and can be represented in mathematical expressions by a constant or a variable

constant quantity (noun)	quantity (noun)
a quantity that does not vary	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