[1] [n] a public issue, a standing problem; a cause célèbre; an issue or incident arousing widespread controversy, outside campaigning and/or heated public debate
[2] [Zen][n] kōan; a story, dialogue, question, or statement in the history and lore of Zen Buddhism, generally containing aspects that are inaccessible to rational understanding, yet may be accessible to intuition, eg. "What is the sound of one hand clapping?"