weakness

Weakness is the state or condition of lacking physical strength, stamina, or the capacity to resist harm. It can describe individuals, systems, or objects, and is often contrasted with strength. A weakness may be temporary or chronic and may arise from health, aging, design flaws, or environmental factors. It is not inherently negative, but it can indicate vulnerability that requires mitigation or adaptation.

Physical weakness refers to reduced vigor or power in muscles and bones. Medical weakness may accompany illness, fatigue, anemia, or chronic conditions. Mental or emotional weakness denotes lower resilience, impulsivity, or difficulty coping with stress. Moral weakness describes failing to act in accord with one's values. Structural or systemic weakness is observed in organizations, processes, or materials that are prone to failure under stress.

Causes include disease, malnutrition, sleep deprivation, dehydration, aging, injury, psychological stress, and insufficient training. In engineering, a weakness is a flaw or vulnerability in design that can lead to failure under load. In security, weaknesses in controls can be exploited. Assessment relies on self-report, clinical evaluation, cognitive testing, endurance measurement, or inspections and testing of materials or structures.

In culture, weakness can be a narrative device that invites empathy or growth, as in stories of overcoming adversity. Philosophers examine moral weakness in relation to virtue and responsibility. In everyday language, Achilles' heel is a common expression for a critical weakness. Recognizing weaknesses is a step toward strengthening resilience, improving safety, or guiding decision-making.