plump down

(verb) drop heavily. Synonyms: plonk down, plump down, plank down.

(verb) set (something or oneself) down with or as if with a noise. Synonyms: plank, flump, plonk, plop, plunk, plump down, plunk down, plump. Examples: "He planked the money on the table." "He planked himself into the sofa."