The term PLUNK (DOWN) can be solved by two crossword solutions: PUT (3 letters) and PLOP (4 letters). PLUNK is a sound effect that is used to describe the sound of an object dropping or hitting a surface. It is often used in cartoons, movies, and other forms of media to indicate a heavy object falling or being thrown. PLOP is a similar sound effect, but it is usually used to describe a lighter object dropping or bouncing off a surface.