Other forms: fizzled; fizzles; fizzling
When something fizzles, it ends in a slow, sad way. Your bake sale may get off to a great start, only to fizzle once you've sold all the brownies and are left with nothing but oatmeal raisin cookies.
The word fizzle has two uses — first, for talking about a failure or disappointment. Your party is a fizzle if no one shows up, and your cheerfulness is bound to fizzle after an experience like that. The second meaning is a hissing or sputtering sound, just like the word itself sounds — like the fizzle of a backyard firework or the fizzle of static on the radio as you switch stations.