PLONKER Meaning of PLONKER in English plonk ‧ er /ˈplɒnkə $ ˈplɑːŋkər, ˈplɒːŋ-/ BrE AmE noun [countable] British English informal not polite an offensive word for a stupid person Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012