plunk

US /plʌŋk/
UK /plʌŋk/
1.

to put something down heavily and without taking care:

:
Just plunk the grocery bags (down) on the table, and come and have some coffee.
1.

a hollow sound like that made when an object is dropped heavily onto a surface:

:
the plunk of a tennis ball
1.

making a hollow sound like that made when an object is dropped heavily onto a surface:

:
I heard something go plunk.