godan verb (-su), transitive verb
slide down; drop into; let slip down
Transitive verb: to cause something to slide or slip downward, often into a container or along a surface. Used for physical objects.
彼はポケットに小銭を滑り落とした。
He slid the coins into his pocket.
箱の中に本を滑り落とす
I slide the book down into the box.