Intestinal fortitude. The head coach of Ohio State University's football team, Dr. John W. Wilce, is said to have invented the word for "guts" in 1915 as "a protest against the lurid language of the gridiron and locker room," guts then being considered "improper for drawing-room conversation." They don't make coaches like Dr. Wilce anymore, nor locker rooms so mild.
Make a clean breast of it. "That man of peace . . . hath been entrusted with King's breasts," someone wrote of an early diplomat. Breast has been a synonym for the heart since ancient times, and like the organ it houses, was long thought to be the seat of consciousness, the repository of all private thoughts, emotions and secrets. To recognize something was to know it on breast as well as learn it by heart, and a person burdened by guilt had a stained breast. These expressions are obsolete now but the phrase to make a clean breast, "to make a full confession or disclosure," has remained part of the language since the early 15th century.
Peeping Tom. According to a later version of the original story, Lady Godiva had but one admirer when she rode nude through the streets of Coventry. The earlier story has everyone in town feasting their eyes on Godiva, but here the plot thickens. Our later version says that a more cunning Lady Godiva issued a proclamation ordering all persons to stay indoors and shutter their windows, so that she could ride naked through Coventry. But enter stage left, Peeping Tom, the unfortunate town tailor, or butcher. Peeping Tom peeped, ruined Lady Godiva's plan, and was struck blind for his peeping -- cruel and unusual punishment for merely being human.