flump
1. [ verb ] fall heavily
Synonyms: flump_down
Related terms: drop
2. [ verb ] set (something or oneself) down with or as if with a noise
Synonyms: plunk plonk plop plump_down plunk_down plump plank
Examples:

"He planked the money on the table" "He planked himself into the sofa"

Related terms: set_down plonk
Similar spelling:   flame_up