drop down
1. . [for someone] to fall down or stoop down. Suddenly, Ted dropped down, trying not to be seen by someone in a passing car. I dropped down as soon as I heard the loud sounds.
2. [for something] to fall from above. The tiles on the ceiling dropped down, one by one, over the years. The raindrops dropped down and gave the thirsty plants a drink.
drop down
(on someone or something) to fall on someone or something. The leaves dropped down on the newly mowed lawn. The wind blew a mighty gust and a thousand leaves dropped down.
drop someone or something down
1. to let someone or something fall. He dropped his pants down, revealing the swimming trunks beneath. The rescuer dropped down the baby and the doctor caught it. Sam went to the well and dropped a rock down.