endurance

This term describes a psychological or physical fortitude that allows a subject to persist through hardship. It carries a connotation of grit and resilience, often implying a slow, grinding struggle rather than a sudden burst of strength. It is frequently used in athletic contexts to describe aerobic capacity or in emotional contexts to describe patience under pressure. As an uncountable noun, it refers to the general quality of being able to withstand stress. However, it can be used as a countable noun when referring to specific types of endurance or the measured duration of a machine's operation, though the uncountable usage is far more common in daily speech.