This is in one respect the inverse of the usual Weird Word. Most featured in this section are in reference works but are rarely used; this one, though, appears in no dictionary I have here, but is a relatively common word among craftspeople who work in glass.
It refers to the action of taking small bites from the edge of a piece of glass with nippers or pliers to trim it to shape. Since no etymological information is directly available, I have to assume it’s derived from the same source as grozing-iron, a term which the Oxford English Dictionary says is long obsolete but which in the nineteenth century was the name for the tool with which glaziers cut glass.
This came from the Dutch gruizen, to crush or grind. It looks very probable that the English verb has been around for at least a century, but as it’s a term limited to one pursuit (not so much jargon as a term of trade) it hasn’t achieved enough circulation for publishers to justify adding it to dictionaries.