plonk

Concise Oxford English Dictionary © 2008 Oxford University Press:
plonk1 informal, chiefly Brit.

▶verb

• 1 set down heavily or carelessly.

• 2 play unskilfully on a keyboard or stringed musical instrument.

▶noun a sound as of something being set down heavily.

– origin C19 (orig. dial.): imitative; cf. plunk.

Concise Oxford English Dictionary © 2008 Oxford University Press:
plonk2

▶noun Brit. informal cheap wine of inferior quality.

– origin 1930s (orig. Austral.): prob. an alt. of blanc in Fr. vin blanc ‘white wine’.