Booby trap/prize

Since the First World War, a booby trap has come to mean a lethal explosive device triggered by touching or moving a seemingly harmless object. Before this, during the 19th century, a booby trap was a harmless prank or trick designed to catch a ‘booby’, which has meant a dunce or stupid fellow since the late 16th century. In the same sense, a booby prize is given as a joke to a loser, but this expression only originated in America in the late 19th century. See also Boob/boobs.