What is the meaning of retentivity?

noun

• The power of retaining and recalling past experience.
  • usage: "he had a good memory when he was younger"
  • synonyms: memory, retention, retentiveness
• The property of retaining possessions that have been acquired.
  • synonyms: retentiveness
• The power of retaining liquid.
  • usage: "moisture retentivity of soil"
  • synonyms: retentiveness, retention