UNDERGLAZE
Etymology
Noun
underglaze (plural underglazes)
A decorative slip applied to the surface of pottery before glazing.
Verb
underglaze (third-person singular simple present underglazes, present participle underglazing, simple past and past participle underglazed)
To apply a decorative slip to the surface of pottery before glazing.
Source: Wiktionary
Un"der*glaze`, a.
Definition: Applied under the glaze, that is, before the glaze, that is,
before the glaze is put on; fitted to be so applied; -- said of
colors in porcelain painting.
Source: Webster’s Unabridged Dictionary 1913 Edition