Wiktionary
underpad
n. 1 A mattress protector. 2 A padding layer underneath a carpet to prevent skidding.
Usage examples of "underpad".
And it was among these notable and austere personagesshort of their customary total by one, for the doyen Chelp had died a few days earlierthat the inventor Yockerbow was summoned to stand today, beneath the interlaced branches of the Doqal Hall, with water plashing underpad.