1525-35; < Latinimpetrātus past participle of impetrāre to obtain by asking, equivalent to im-im-1 + -petrā(re), combining form of patrāre to bring to completion, accomplish, derivative of paterfather + -tus past participle suffix
C16: from Latin impetrāre to procure by entreaty, from -petrāre, from patrāre to bring to pass, of uncertain origin; perhaps related to Latin pater a father