denseness vs spacing

denseness and spacing both are nouns.

Word	Noun	Adjective	Verb	Adverb
denseness	Yes	No	No	No
spacing	Yes	No	No	No

As nouns, spacing is a hypernym of denseness; that is, spacing is a word with a broader meaning than denseness:

denseness: the spatial property of being crowded together
spacing: the property possessed by an array of things that have space between them

Other hypernyms of denseness include spatial arrangement.

denseness (noun)	spacing (noun)
the amount per unit size	the property possessed by an array of things that have space between them
the spatial property of being crowded together	the time between occurrences of a repeating event
the quality of being mentally slow and limited