Dictionary Definition
retentivity n : the power of retaining liquid;
"moisture retentivity of soil" [syn: retentiveness, retention]
Extensive Definition
The retentivity of a material is its capacity to
remain magnetized
after the external magnetizing
field has ceased to exist.
A material with high retentivity (i.e. iron) will keep some magnetic
properties, it will become a permanent
magnet, whereas a material with low or no retentivity will not
keep the magnetic properties—it will lose its
magnetization.