memory vs retentivity

memory and retentivity both are nouns.

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

As nouns, memory and retentivity are synonyms defined as:

memory and retentivity: the power of retaining and recalling past experience

Other synonyms of memory include retention, retentiveness.

memory (noun)	retentivity (noun)
an electronic memory device	the power of retaining liquid
the power of retaining and recalling past experience	the property of retaining possessions that have been acquired
the cognitive processes whereby past experience is remembered	the power of retaining and recalling past experience
something that is remembered
the area of cognitive psychology that studies memory processes