[ roo-bee ]
/ ˈru bi /
Save This Word!

noun, plural ru·bies.
ruby-colored: ruby lips.
containing or set or adorned with a ruby or rubies: a ruby necklace.
Do you know the difference between everyday US and UK terminology? Test yourself with this quiz on words that differ across the Atlantic.
Question 1 of 7
In the UK, COTTON CANDY is more commonly known as…

Origin of ruby

First recorded in 1300–50; Middle English noun rubi from Old French, from Old Provençal robi(n) , from Medieval Latin rubīnus (lapis) “red (stone),” derivative of Latin ruber, rubeus red1


ru·by·like, adjective

Other definitions for ruby (2 of 2)

[ roo-bee ]
/ ˈru bi /

a female given name.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023


What does ruby mean?

A ruby is a transparent red gemstone. Rubies are one of the most well-known gemstones, along with diamonds, emeralds, and sapphires.

They are classified as precious gems, meaning that they have a high commercial value. Rubies are quite rare and are considered one of the most valuable gems. Besides diamond, ruby is one of the hardest known natural substances.

The ruby is the traditional birthstone for the month of July. It is associated with the zodiac signs Capricorn and Leo.

The word ruby is also used to refer to a jewel-toned red color or describe things that are that color. The word is often used in the term ruby red, as in Look at that ruby red sports car! 

The word ruby is sometimes used to describe a 40-year anniversary, as in It’s my parents’ ruby anniversary this year—I can’t believe they’ve been married for 40 years!

Ruby is also a given name, traditionally a female one.

It’s also the name of a programming language.

Example: The ring features a large ruby surrounded by diamonds. 

Where does ruby come from?

The first records of the word ruby come from the 1300s. It comes from the Medieval Latin rubīnus (lapis), meaning “red (stone).” It ultimately derives from the Latin ruber or rubeus, meaning “red.”

Rubies are a red variety of the mineral corundum, a form of aluminum oxide. Traces of chromium and other minerals are responsible for its brilliant red coloring. (Sapphires are a blue variety of corundum.)

Historically, rubies have been mined primarily in Myanmar and Sri Lanka, though they can be found in other places. Some rubies are synthetic, meaning they are manufactured in a lab.

Did you know … ?

What are some synonyms for ruby?

What are some words that share a root or word element with ruby

What are some words that often get used in discussing ruby?

How is ruby used in real life?

Rubies are one of the most well-known gems. The word ruby is often used to describe things that are a deep, jewel-toned red, especially in the term ruby red.

Try using ruby!

True or False?

Rubies and sapphires are different varieties of the mineral corundum.

How to use ruby in a sentence

British Dictionary definitions for ruby

/ (ˈruːbɪ) /

noun plural -bies
a deep red transparent precious variety of corundum: occurs naturally in Myanmar and Sri Lanka but is also synthesized. It is used as a gemstone, in lasers, and for bearings and rollers in watchmaking. Formula: Al 2 O 3
  1. the deep-red colour of a ruby
  2. (as adjective)ruby lips
  1. something resembling, made of, or containing a ruby
  2. (as modifier)ruby necklace
(modifier) denoting a fortieth anniversaryour ruby wedding
(formerly) a size of printer's type approximately equal to 5 1/2 point

Derived forms of ruby

ruby-like, adjective

Word Origin for ruby

C14: from Old French rubi, from Latin rubeus reddish, from ruber red
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for ruby

[ rōōbē ]

A deep-red, translucent variety of the mineral corundum, containing small amounts of chromium and valued as a gem. Compare sapphire.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.