Among the more interesting elements of etymology is the attempt to derive the meaning of seemingly nonsensical expressions.Take, for instance, the increasingly archaic rural phrase “to buy a pig in a poke.” For centuries, the expression has been used to signify the purchase of an item without full knowledge of its condition, and it relates to the common Renaissance practice of securing suckling pigs for transport to market in a poke, or drawstring bag.Unscrupulous sellers would sometimes attempt to dupe purchasers by replacing the suckling pig with a cat, considered worthless at market.An unsuspecting or naive buyer might fail to confirm the bag's contents; a more urbane buyer, though, would be sure to check and—should the seller be dishonest—"let the cat out of the bag."
