plump down
1. To fall, drop, set, or sit down very heavily, suddenly, or abruptly. He came in from work and plumped down on the sofa without a word. The huge St. Bernard came over and plumped down onto her bed by the fireplace.
2. To drop or set someone or something down very heavily, suddenly, or abruptly. In this usage, a noun or pronoun can be used between "plump" and "down." The courier plumped the package down on my desk, nearly knocking over my coffee cup in the process. He plumped the screaming child down on the couch and put on some cartoons to calm her down.
plump something down
1. to drop a heavy load of something. She plumped the load of groceries onto the bench and looked through her purse for the keys. Jill plumped down her packages.
2. to drop something as if it were a heavy load. He plumped the potatoes down on each plate, making a loud noise each time. Dave plumped down a huge slab of meat onto the grill.