in·sti·ga·tion \ˌ ̷ ̷ ̷ ̷ˈgāshən\noun (-s) Etymology: Middle English instigacioun, from Middle French or Latin; Middle French instigation, from Latin instigation-, instigatio, from instigatus (past participle) + -ion-, -io -ion 1.: an act of instigating or the state of being instigated : incitement < they agreed at our instigation to confer > < the instigation of the new program > 2.: something that instigates : incentive < his friends' approval was a real instigation to succeed >