parison
A spherical mass of glass, rolled immediately after being taken out of the furnace.
The wineglasses were from a matched dozen, each having begun as a glowing parison at the end of some blowpipe over in Murano but days before.
Where it comes from
From French paraison, from parer (“pare”). Doublet of paration.
Adapted from the Wiktionary entry parison (CC BY-SA 4.0).