What are the opposite words for weakness?

Strength would be the most common antonym for the word "weakness". Other antonyms could include vigor, resilience, power, fortitude, might, and durability. All of these words connote a sense of being able to overcome challenges that would be overwhelming for one who is weak. Someone who possesses strength has the ability to push through challenges or obstacles without being defeated, and might be admired for their resilience in the face of adversity. In contrast, weakness suggests a lack of power or ability to overcome obstacles, which can cause a person to feel vulnerable and unable to protect themselves.