plunk

To plunk is to abruptly drop an object (or yourself). Your daily routine, for example, might include rushing home after school so you can plunk yourself on the couch to play video games.

There are various ways to plunk: A waiter might plunk your hamburger on the table, and you could choose to plunk down a buck as a tip. You can also plunk the string of a guitar or other instrument, by plucking it casually or inexpressively: "I don't really know how to play the ukulele — I just like to plunk the strings." This last meaning is the original one, from an imitation of the sound of a plunk.