seal (v.) 2
accomplish, carry out, fulfil
CE I.i.9 [Duke to Egeon, of the Duke of Syracuse and the merchants] Have sealed his rigorous statutes with their bloods
Tim V.iv.54 [Second Senator to Alcibiades] all thy powers / Shall make their harbour in our town till we / Have sealed thy full desire
TNK I.ii.92 [Valerius to Palamon and Arcite, of Theseus] who is at hand to seal / The promise of his wrath
TNK IV.ii.87 [Messenger to Theseus, of one of Arcite's knights] a sword ... when he frowns / To seal his will with [i.e. with which he carries out his intentions, when he is angry]