play a keyboard or plucked stringed instrument in an inexpressive way

I got a guitar when I was twelve and started plunking away on it

hit (someone) abruptly

he plunked him in the back

set down heavily or abruptly

she plunked her pack on top of the bar

the sound made by abruptly plucking a string of a stringed instrument

the singing was punctuated by the plunks of the guitar

a heavy blow.