1670s, as the fidget "uneasiness," later the fidgets, from a verb fidge "move restlessly" (16c., surviving longest in Scottish), perhaps from Middle English fiken "to fidget, hasten" (see fike (v.)).
1670s (implied in fidgetting); see fidget (n.). Related: Fidgeted.
The child is always fidgeting in his seat
he's got the fidgets