module vs retentivity

module and retentivity both are nouns.

Word	Noun	Adjective	Verb	Adverb
module	Yes	No	No	No
retentivity	Yes	No	No	No

As nouns, retentivity is a hyponym of module; that is, retentivity is a word with a more specific, narrower meaning than module:

module (noun)	retentivity (noun)
a self-contained component (unit or item) that is used in combination with other components	the power of retaining liquid
computer circuit consisting of an assembly of electronic components (as of computer hardware)	the property of retaining possessions that have been acquired
detachable compartment of a spacecraft	the power of retaining and recalling past experience
one of the inherent cognitive or perceptual powers of the mind