To get ready for trouble. A nautical term dating from the early nineteenth century, it signified preparing for bad weather by fastening down the battens, strips of wood nailed to various parts of masts and spars, and fastening tarpaulins over the ship’s hatchways (doorways and other openings). The term began to be used figuratively as preparing for any emergency by the late nineteenth century. See also clear the decks.

Don’t spend or try to profit from something not yet earned. This expression comes from Aesop’s fable about a milkmaid carrying a full pail on her head who daydreams about selling the milk for eggs that will hatch into chickens and make her so rich she will toss her head at offers of marriage; but she prematurely tosses her head and spills the milk. It was, like so many Greek fables, translated into modern European languages and passed on. The expression was in use figuratively by the sixteenth century and appeared in proverb collections soon afterward.

Drink it down, a toast for drinkers. The allusion is to the naval hatch, an opening in a ship’s deck through which cargo, passengers, or crew can pass. The transfer to the human mouth or throat was made long before this slangy expression came into use. John Heywood’s 1546 proverb collection included, “It is good to haue a hatche before the durre,” meaning it is good to have some impediment to speaking before one opens one’s mouth, so as to have time to reflect. The metaphor also appears in Stephen Gosson’s The Schoole of Abuse (1579): “I wish that every rebuker shoulde place a hatch before the door.” The drinker’s meaning, however, is a twentieth-century expression, first appearing in print in the early 1930s, as in Malcolm Lowry’s Ultramarine (1933): “Well, let’s shoot a few whiskies down the hatch.”