おとろotoroえるeru
1.

To experience a reduction in strength or vitality, diminishing in effectiveness or activity over time.

2.

To undergo a gradual process of decline, leading to a loss of vitality, presence, or significance.

3.

To fade or weaken, particularly in terms of physical capabilities or qualities, reflecting a state of deterioration.

4.

To decline in status or condition, often implying a shift from a once-flourishing state to one of lesser importance or performance.

Example:

私は体力が衰えた。