a confusing and difficult problem or question 复杂难题 one of the most difficult conundrums for the experts. 对专家们来说最难的难题之一。 ■a question asked for amusement, typically one with a pun in its answer; a riddle (尤指答案中含双关语的)谜语
语源
late 16th cent.: of unknown origin, but first recorded in a work by Thomas Nashe, as a term of abuse for a crank or pedant, later coming to denote a whim or fancy, also a pun. Current senses date from the late 17th cent