Agility is the ability to move quickly, easily, and with control. A gymnast demonstrates agility when she springs from one apparatus to another, changing direction smoothly in mid-air. A running back in football shows agility when he dodges defenders, pivoting and accelerating without losing his balance.

True agility combines speed with coordination. A cheetah sprinting in a straight line is fast, but when it zigzags after prey at full speed, it's showing agility. Your cat displays remarkable agility when it leaps onto a narrow fence, lands perfectly, then instantly jumps to another surface.

The word also describes mental quickness. When you solve a puzzle by trying different approaches rapidly, switching strategies when one doesn't work, you're showing mental agility. In business, a company with agility can quickly adapt when customers want something new.

Agile is the adjective form: an agile mind, an agile athlete, an agile lizard darting between rocks. Athletes train for agility by practicing quick changes of direction, like running through a zigzag course of cones. The combination of speed, balance, and control makes agility valuable in sports, nature, and problem-solving.