skitter v.

early 15c., "very lively, frivolous," perhaps from a Scandinavian word related to Old Norse skjota "to shoot, launch, move quickly," from PIE root *skeud- "to shoot, chase, throw." Compare Northern dialect skite "to move by leaps and bounds" (see skit).

The sense of "shy, easily frightened, nervous, apt to run" is by c. 1500, of horses. The meaning "changeable, fickle, inconstant" is from c. 1600; that of "inclined to be coy or reserved" is from 1640s. Related: Skittishly; skittishness.

1820, "piece of light satire or caricature, lampoon," from the earlier sense of "a satirical remark or reflection" (1727), which apparently is from an earlier still sense of "a light wench; a vain, frivolous, or wanton girl" (1570s, originally Scottish, now archaic).

This is said to be from or related to a verb skit "go off suddenly; shy or be skittish" (1610s), which is of uncertain origin, perhaps ultimately from Old Norse skjuta "to shoot, move quickly," cognate of Old English sceotan (see shoot (v.)), or perhaps it is a back-formation from skittish.