The Collaborative International Dictionary
Frostwork \Frost`work"\, n. The figurework, often fantastic and delicate, which moisture sometimes forms in freezing, as upon a window pane or a flagstone.
Wiktionary
n. Any naturally occurring intricate pattern of ice crystals
Wikipedia
thumb|upright=1.75|alt=frostwork|Frostwork in Jewel Cave, South Dakota.
In geology, frostwork is a type of speleothem (cave formation) with acicular ("needle-like") growths almost always composed of aragonite (a polymorph of calcite) or calcite replaced by aragonite. It is a variety of anthodite. In some caves frostwork may grow on top of cave popcorn or boxwork.
In architecture frost-work or frostwork refers to a style of rustication carved with a vertically-oriented pattern evoking hanging pond-weed or algae, or icicles. It is mainly found in garden architecture, where water is to flow over or near the surface. Other decorative arts may use the term for other decorative patterns imitating frost or ice.
Usage examples of "frostwork".
I kept tossing about, drinking water, sitting up in bed and gazing at the frostwork on the window.
She, too, shaded her eyes with her hand, and through the blurred frostwork of the window I saw a blurred face.