pace vs indefinite quantity

pace and indefinite quantity both are nouns.

Word	Noun	Adjective	Verb	Adverb
pace	Yes	No	Yes	No
indefinite quantity	Yes	No	No	No

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

pace (noun)	indefinite quantity (noun)
a step in walking or running	an estimated quantity
the relative speed of progress or change
a unit of length equal to 3 feet; defined as 91.44 centimeters; originally taken to be the average length of a stride
the distance covered by a step
the rate of moving (especially walking or running)
the rate of some repeating event