"quick, energetic," 1825, from snap (v.) + -y (2). Meaning "clever, smart" is from 1871; that of "neat and stylishly elegant" is from 1881. Related: Snappily; snappiness. Command make it snappy attested from 1910.
To hurry; go faster; act quickly; get the lead out, snap to it (1915+)
make it snappy