靴子落地

(lit.) the boot hits the floor (idiom) / (fig.) a much-anticipated, impactful development has finally occurred (an allusion to a joke from the 1950s in which a young man would take off a boot and throw it onto the floor, waking the old man sleeping downstairs who could then not get back to sleep until he had heard the second boot hit the floor)

日本語訳なし – 英語の意味