"apr" is an abbreviation for "April," which is the fourth month of the year in the Gregorian calendar. It does not directly relate to the clue "When fools rush in?" Please provide more context or clarify the clue if you are referring to a different meaning of "apr."
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Mo. when the Titanic sank. Explanations are generated by AI and may be inaccurate.