Light on one’s feet

The answer to the crossword question “Light on one’s feet is SPRY” is referring to the adjective “spry,” which means to be agile, active, and lively. Thus, if someone is “light on their feet,” meaning they are nimble and quick, they could also be described as “spry.” The word “spry” is often used to describe older people who have maintained their physical abilities and are still active and lively despite their age. Overall, the answer to the crossword question is indicating that the word “spry” is a synonym for being light on one’s feet.