The Word Detective explains that the phrase probably originated with the Irish “seibin,” which is a small mug. “Shebang” first appears during the Civil War to describe a hut, shed, or some other kind crude makeshift shelter for soldiers. At about the same time “shebang” started being used to mean a vehicle and a rented coach in particular. “Shebang” has also been used to describe a disreputable tavern or hotel that is also called a “dive.” Today it is most commonly used to describe the entire thing or matter.

It is universally accepted that the expression means that someone is blissfully happy, but there are debates about the origin. Askville writes that it was popularized by the Johnny Dollar radio show in the 1950s when the “…hero was knocked unconscious and transported to Cloud Nine.” Many think, or have thought, that the origin was the U.S. Weather Bureau which rates Level Nine as the very highest cumulonimbus clouds. Another theory is that it is derived from Buddhism in which “In the ninth stage the seeker reaches when all his acts are unselfish…” Then there is Dante’s Paradise in which the ninth level of heaven is the closest to the Divine Presence. If that doesn’t confuse you sufficiently, contemplate that the number nine turns up in other expressions with disputed origins such as “dressed to the nines” and “the whole nine yards.” Is searching for origins fun, frustrating, or interesting?

Yahoo Answers has an explanation that the “…Greeks believed that jealously was accompanied by an overproduction of bile, lending a yellowish-green pallor to the victim’s complexion.” A seventh century B.C. poetess described the face of a stricken lover as green. Shakespeare’s Othello mentioned that jealously “…is the green-ey’d monster…”

Straight Dope has a detailed discussion of how yellow became associated with cowardice. It is speculated that the source was the medieval medicine theory that the four body fluids were blood, phlegm, black bile, and yellow bile. Yellow bile was said to make you peevish, choleric, or irascible. The color yellow was subsequently used to mark the doors of the homes of French traitors. Victims of the Spanish inquisition had to wear yellow, and Nazis used a yellow star to designate that a person or business was Jewish. A yellow flag was used to quarantine victims of yellow fever. “Yellow journalism” dates from about 1895 and was and is used to describe news using sensational headlines and articles to inspire fear.

A grandson asked where this expression came from. The Phrase Finder writes that a popular but incorrect origin is that the Royal Navy served meals on square wooden plates. The expression is of U.S. origin and is based on the use of the word “square” to mean proper and honest. The earliest written reference was in a November 1856 advertisement in the newspaper The Mountain Democrat for the Hope and Neptune restaurant. The ad promised a “square meal” of “oyster, chicken, and game prepared at short notice.”

Nickname is a corruption of what was originally called an “eke name.” “Eke” meant “also” or “extra,” so naturally “nickname” means to have an extra name.