numerosity

plural numerosities

1. uncountableThe condition of being numerous.
2. countableThe extent to which something is numerous.

   We suggest that for small numerosities, the preverbal counter can run much faster than the verbal counting routine, so that the magnitude (the preverbal numeron) that represents the numerosity of an array is specified long before the verbal counting process has arrived at the correct numerlog.

   2013, William Kessen, Andrew Ortony, Fergus Craik, Memories, Thoughts, and Emotions, page 76

3. countableobsoleteuncountableHarmonious flow.