What Does My Name Ruby Jean Mean?

Ruby is one of the "gemstone" names that first became popular in the 19th century (Pearl and Beryl are other examples.) It simply means a ruby, ie the red precious stone, which gets its name from the Latin rubeus, or "red." Ruby became quite a rare name in the later 20th century, but it is now becoming popular again.

Jean, like Jane and Joan, is a version of the old French name Jehanne (now Jeanne) which itself is a feminine form of the name John. John derives from the very old Hebrew name Johanan, meaning "God is Merciful" or "God is Gracious." Jean has always tended to be more popular in Scotland than elsewhere, though it can be found all over the English-speaking world. It is also quite often used as a middle name (as in your case) - famous examples include Marilyn Monroe's real name, Norma Jean Baker.