A prop used to support pottery in a kiln, so as to expose the bottom of the piece to the full heat.
Origin
Late 19th century; earliest use found in Edward H. Knight (1824–1883), patent lawyer and expert in mechanics. From French pernette prop used to support pottery in a kiln from Occitan perneta from Old Occitan pern big nail with large head or its etymon perna joint of salted meat, child's blanket + -eta, diminutive suffix.