Where does “rumpfuschen” come from?

rumpfuschen (German) comes from German pfuschen, from German futsch — down the drain, gone, away.

Ancestry of “rumpfuschen”, step by step

Step	Language	Word	Meaning
1	German	pfuschen	to work unprofessionally; to botch; to cheat; to...
2	German	futsch	down the drain, gone, away