Here are yet more origins of some common phrases.
Meaning: Certain to succeed
Origin: “This term refers to the container in which hunters placed small game, called a ‘bag’ since the 15th century. It began to be used figuratively for a virtual certainty in the 20th century, at first in America. The Emporia Gazette used the phrase in describing Gene Tunney’s victory over heavyweight champion Jack Dempsey in 1926: ‘After Tunney landed with that terrific right, the fight was in the bag.’” (From Southpaws & Sunday Punches, by Christine Ammer)
Meaning: In the nude; to polish something
Origin: “These expressions are rooted in the buffalo hide craze of the 19th century. In the buff is from the soft yellow skins made from buffalo hides, which looked a little like bare human skin. To buff comes from the strips of buffalo hide that were used to polish metals.” (From Word and Phrase Origins, by Robert Hendrickson)
Meaning: To obtain something one way or another
Origin: “In 1100 William Rufus, king of England, was slain by an arrow while out hunting in the New Forest. A charcoal burner named Purkiss found the king’s body and took it by cart to Winchester. As a reward Purkiss was allowed to gather wood from the New Forest—all that could be reached by a shepherd’s crook and cut down with a billhook.” (From Everyday Phrases, by Neil Ewart)
Meaning: Unreliable or untrustworthy (often a business)
Origin: “Even as recently as a century and a half ago this meant a witch, one who actually mounted her broom at midnight and went off on her round of appointments, whatever they may have been, or to meet secretly the Old Boy himself.” (From Heavens to Betsy!, by Charles Earle Funk)
Look out! The continent of Australia is drifting northward at a rate of 2.25 inches per year.