Final answer:
Hibernation is the seasonal cessation of activities accompanied by a reduction in metabolism in response to cold temperatures during winter. Animals that hibernate enter a state of torpor, which lowers their metabolic rate and helps them conserve energy.
Step-by-step explanation:
The seasonal cessation of activities accompanied by a reduction in metabolism in response to cold temperatures during winter is called hibernation. Animals that hibernate enter a state of torpor, which is a condition in which their metabolic rate is significantly lowered. This enables them to conserve energy and wait until their environment better supports their survival.