retentivity

If required for permanent magnet making, it should have the highest possible coercivity combined with a high retentivity.

The professor himself often comes to class armed with notes, but he persists in setting up, as a test of the growth of his students, their retentivity of the facts he gave from these very notes.

Mars is an older world than ours, and although it receives only one-half as much heat from the sun yet it is almost of the same temperature, owing to a peculiar condition of the atmosphere which we would call "heat retentivity."