Other forms: rubies
A ruby is a hard red precious stone. A ruby ring, set with rubies, deep red ruby.
It is corundum, the same mineral as sapphire, and only the red kind is called a ruby — chromium is what makes it red. It is second only to diamond in hardness. A ruby wedding is the fortieth anniversary. Note that ruby is also the colour, and that the name comes from the Latin for red.
1nounrubyA hard red precious stone.
“Her engagement ring had a ruby in the middle and small diamonds around it.”
ruby is a gemstone.
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Etymology from Wiktionary, CC BY-SA