A volcanic bomb is a large fragment of molten rock ejected during a volcanic eruption that solidifies before reaching the ground. Volcanic bombs are significant in volcanology for understanding the mechanisms of explosive eruptions, the size and distribution of pyroclastic material, and the hazards posed to areas near active volcanoes.
Reference: Fisher, R. V., & Schmincke, H.-U. (1984). “Pyroclastic Rocks.” Springer.