The Collaborative International Dictionary
Pontil \Pon"til\, n. Same as Pontee.
Wiktionary
alt. (context glassblowing English) A punty; a metal rod used in the glassblowing process. After a glass vessel has been blown to approximate size and the bottom of the piece has been finalized, the rod, which is tipped with a wad of hot glass, is attached to the bottom of the vessel to hold it while the top is finalized. It often leaves an irregular or ring-shaped scar on the base when removed called the "pontil mark". n. (context glassblowing English) A punty; a metal rod used in the glassblowing process. After a glass vessel has been blown to approximate size and the bottom of the piece has been finalized, the rod, which is tipped with a wad of hot glass, is attached to the bottom of the vessel to hold it while the top is finalized. It often leaves an irregular or ring-shaped scar on the base when removed called the "pontil mark".
Wikipedia
Usage examples of "pontil".
At the exact moment when the work was cool enough to stand he attached the pontil with its drop of liquid glass to the lower end, as he had done many a time in the laboratory, and before those who looked on could fully understand how he had done it without assistance, the long and heavy blow-pipe lay on the floor and Zorzi held his piece on the lighter pontil, heating it again at the fire.
He left the cooling piece on the pontil, lying across the arms of the stool, and took his blow-pipe again.