1.  snappy(s = adj.all) snappish - apt to speak irritably; "a snappish tone of voice"

2.  snappy(s = adj.all) whipping - smart and fashionable; "snappy conversation"; "some sharp and whipping lines"

3.  snappy(s = adj.all) crisp, frosty, nipping, nippy - pleasantly cold and invigorating; "crisp clear nights and frosty mornings"; "a nipping wind"; "a nippy fall day"; "snappy weather"
Derived forms noun snap₁₂, noun snap₂

4.  snappy(s = adj.all) dapper, dashing, jaunty, natty, raffish, rakish, spiffy, spruce - marked by up-to-dateness in dress and manners; "a dapper young man"; "a jaunty red hat"

5.  snappy(s = adj.all) alert, brisk, lively, merry, rattling, spanking, zippy - quick and energetic; "a brisk walk in the park"; "a lively gait"; "a merry chase"; "traveling at a rattling rate"; "a snappy pace"; "a spanking breeze"

   Snappish. [1913 Webster]

snappy, adj. (snappier, snappiest) colloq.
1 brisk, full of zest.
2 neat and elegant (a snappy dresser).
3 snappish.

Idiom:
make it snappy be quick about it.

Derivative:
snappily adv. snappiness n.