Another related term is "Hipot". An
adjustable high-voltage source
with an insulated probe. Indispensible for testing (sometimes
destructively) susceptibility to ESD, although I suspect a cat and a
pair of rubber-soled shoes might work as well.
Hence the 'Hipot tested' labels you sometimes see on things.
There's also a 'flash tester' whcih is like a high votlage megger that
only provides a high voltage pulse. You might flash-test the windings of
a mains transformer to the cor are 4kV or so.
-tony