Final answer:
The term is 'density-dependent mortality,' which means death rates increase as population density increases due to factors like disease spread and competition.
Step-by-step explanation:
The term that describes death occurring more quickly in a crowded population than in a sparse population is related to density-dependent factors. In biology, when the density of a population increases, so too does the likelihood of mortality due to increased competition, spread of diseases, and stress on resources. Diseases spread more rapidly in high-density populations, affecting the mortality rate significantly. An example includes the rapid transmission of infectious diseases in densely populated areas, leading to higher mortality rates as seen in historic events like the Black Death.