instigation (n.) Look up instigation at Dictionary.com
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.)).