Sniggleflop

The spontaneous and uncontrollable laughter that ensues when someone attempts to stifle a sneeze in a room full of people, resulting in a peculiar combination of snorts, giggles, and snorts that sound like a cross between a snicker and a flop

Example: Jane tried to hold in her sneeze during the important meeting, but the entire room erupted in sniggleflops, making it impossible for anyone to take the presentation seriously.