'Retentivity' definitions:

Definition of 'retentivity'

(from WordNet)
noun
The power of retaining and recalling past experience; "he had a good memory when he was younger" [syn: memory, retention, retentiveness, retentivity]
noun
The property of retaining possessions that have been acquired [syn: retentiveness, retentivity]
noun
The power of retaining liquid; "moisture retentivity of soil" [syn: retentiveness, retentivity, retention]

Definition of 'Retentivity'

From: GCIDE
  • Retentivity \Re`ten*tiv"i*ty\, n. The power of retaining; retentive force; as, the retentivity of a magnet. [1913 Webster]