FLUMP
plank, flump, plonk, plop, plunk, plump down, plunk down, plump
(verb) set (something or oneself) down with or as if with a noise; “He planked the money on the table”; “He planked himself into the sofa”
flump, flump down
(verb) fall heavily
Source: WordNet® 3.1
Etymology
Verb
flump (third-person singular simple present flumps, present participle flumping, simple past and past participle flumped)
(intransitive) To move or fall heavily, or with a dull sound.
(transitive) To drop something heavily or with a dull sound.
Noun
flump (plural flumps)
The dull sound so produced.
A type of large marshmallow.
(by extension) A fat out-of-shape person.
Synonyms
• plunk, thud
Anagrams
• Pflum
Source: Wiktionary