noun Chiefly British.
Origin of plonk
Examples from the Web for plonk
Just cobble it together, plonk it on your head, and smile a lot.
Why not plonk yourself and your guests in front of the warm glow of the television set this holiday weekend?
Suddenly we heard a musical and distant wail, something flew past the window, and there was a wee "plonk."A Company of Tanks|W. H. L. Watson
Word Origin for plonk
1874, imitative. From 1903 as a noun. Related: Plonked; plonking.