Nimble
Part of speech: adjective
Definition: Quick and light in movement or action. Quick-witted and alert.
Example sentence: Moderating a debate means spending more time with briefing books than with your children. It means writing and rewriting and rephrasing. It means finding a way to be alert enough to notice when your question goes unanswered and nimble enough to decide what you will do about that on the spot.
Spry
Part of speech: adjective
Definition: Having great power of leaping or running; nimble; active.