pyroid

1. not comparablechemistryPertaining to noble metals, such as gold and silver.

   By warming with pyridine, H. H. Schlubach1 was able to force the equilibrium between the pyroid and furoid modification of galactose so far toward the furoid form, that the β-pentacetylgalactofuranose was prepared in practical quantities.

   1943, Ole Gisvold, Charles Herbert Rogers, The Chemistry of Plant Constituents, page 79

2. not comparableHaving a tapered shape.

   The females were pyroid in shape, without any neck.

   1979, Y. Chaturvedi, S. Khera, Studies on Taxonomy, Biology, and Ecology of Nematodes, page 89

plural pyroids

1. countableuncountablePyrolytic graphite.

   Both basal-oriented and edge-oriented (basal planes perpendicular to the surface) samples of pyroid were implanted.

   1976, Manfred Kaminsky, Radiation Effects on Solid Surfaces, page 99