instigation (n.)
early 15c., from Middle French instigation and directly from Latin instigationem (nominative instigatio), noun of action from past participle stem of instigare "urge on, incite," from in- "in" (see in- (2)) + *stigare, a root meaning "to prick," from PIE root *steig- "to prick, stick, pierce" (see stick (v.)).