plump for someone or something
to support or promote someone or something. Henry spent a lot of energy plumping for Bill, who was running for vice president. She spent a lot of time plumping for our candidate.
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.
plump something up
to pat or shake something like a pillow into a fuller shape. Todd plumped his pillow up and finished making the bed. He plumped up his pillow.