Within gaming, notably
First Person Shooters (FPS), to end one's life using
explosives in a sacrificial yet joyful manner. And example of this is running up to an enemy and throw an explosive at both of your feet. The resulting explosion kills you both.
The original origin of the term comes from the novel series "Malazan Book of the Fallen" by Steven Erikson. Within the story, one of the sappers (or combat engineer) uses a 'cusser', which is an extremely explosive alchemical clay ball to save his squad and kill an enemy demon by running up to it and throwing it at the ground.
The act is only half of the process. One must be excited, or jubilant, possibly uttering a celebratory cry of triumph.