Plonk is a non-specific and derogatory term used primarily in British and Australian English for cheap, low-quality wine. It is believed to come from Australian slang, in reference to blanc (the French word for "white"), before it became naturalised in Britain.

What does the British term plonk mean?

chiefly British. : cheap or inferior wine.

What does plonk mean in the police?

plonk (plural plonks) (countable, dated, Britain, law enforcement slang) A female police constable. [