Resilience
A commonly used term to describe string responsiveness. Similar to elasticity, a more resilient string is more responsive or lively, providing greater ball speed or power. Specifically, resilience is the speed at which a string (or web of strings in a strung racquet) return to their original position after contacting the ball. Over time, strings lose their resilience, returning less energy to the ball. This loss of resilience causes the strings to play “dead”.