To spoil someone’s plans or celebration. This term, which calls up a vivid image of a downpour spoiling elaborate floats and dampening spirits, has been around since about 1900. Sheila Rule, reporting on a plan to replace Britain’s House of Lords with an elected second chamber, wrote, “But the opposition Labor Party, which has long sought to rain on the Lords’ political parade, is once again aiming at those men and women” (New York Times, 1990).