set (something) down heavily or unceremoniously

she plumped her bag on the table

an abrupt plunge; a heavy fall

the wagon came into a deep hole, with such a plump

a flock of wildfowl

a plump of ducks rose at the same time

shake or pat (a cushion or pillow) to adjust its stuffing and make it rounded and soft

she plumped up her pillows

I was running from the kitchen to the living room, plumping the cushions and getting drinks in place