The answer to the Sudden plunging river like at Iguazú or Niagara in CodyCross is WATERFALL. CodyCross is an amusing word game. It is a word play game that challenges one's word knowledge in different categories and themes. If this clue had you baffled, you're not alone! Many of the puzzles in CodyCross are pretty tricky, but that's what makes the game so fun.