A fabric, often silk, which has a watery or wavelike appearance.
A pattern that emerges when two grids are superimposed over one another, sometimes unintended or undesirable in many applications such as in weaving and screenprinting.
To give a watered or clouded appearance to (a surface).
opal glass
any of several minerals resembling opal, including a variety of yellow chalcedony
a clear to white liquid secreted by sea hares (genus Aplysia) that becomes viscous upon contact with water
resembling opal in its iridescence; having a milky white iridescence.