1. Drop heavily
   "He plumped down on the couch after a long day";
   - plonk down [informal], plank down [informal]
    
2. Set (something or oneself) down with or as if with a noise
   "He plumped down the money on the table";
   - plank [informal], flump [informal], plonk [informal], plop, plunk [informal], plunk down [informal], plump, slap

Derived forms: plumps down

Type of: drop, place down, put down, set down