Agile, Nimble, Brisk and Spry mean acting or moving with quickness and alacrity.
Agile implies dexterity and ease in the management of one’s limbs or, by extension, one’s wits.
- agile as a monkey
- in a flow of racy comment, skimming from one topic to another with an agile irrelevance
—Rose Macaulay
Nimble suggests surpassing lightness and swiftness of movement or action, and often implies a darting here and there.
- nimble as a squirrel
- Madame Defarge knitted with nimble fingers
—Dickens - nimble feet scudding over the springy turf
—Webb
Brisk implies liveliness, animation, or vigor of movement
- a brisk canter
- a brisk walking pace
- to have brisk and intelligent talk
—Benson
It is sometimes applied to things that do not move but are invigorating or exhilarating.
- brisk day
- brisk reply
- she walked briskly in the brisk air
—George Eliot
Spry stresses alacrity arising from vigor or health; however it is frequently applied to those from whom alacrity or briskness of movement is not to be expected.
- the old lady is as spry as a cricket
- she is down one day, and up and spry the next