Is this really hysteresis or just a thermostat that is designed to
turn off at a lower temperature than it turns on at?
Meirman

n. pl. hys·ter·e·ses [ -sz ]

The lagging of an effect behind its cause, as when the change in magnetism
of a body lags behind changes in the magnetic field.

Not *hysteresis* according to Webster. But language is an evolving art and
Webster is sometimes slow in catching up with technical jargon. I have used
and heard *hysteresis* used in the same sense as by the previous poster and
it has always been understood.

SJF