- gold, Au, atomic number 79 - a soft yellow malleable ductile (trivalent and univalent) metallic element; occurs mainly as nuggets in rocks and alluvial deposits; does not react with most chemicals but is attacked by chlorine and aqua regia
--1 is a kind of noble metal
--1 is a substance of
--1 has particulars: gold dust; green gold; guinea golddental gold; sylvanite, graphic tellurium; gold foil; gold leaf; gold - Astronomical Unit, AU - a unit of length used for distances within the solar system; equal to the mean distance between the Earth and the Sun (approximately 93 million miles or 150 million kilometers)
--2 is a kind of astronomy unit