surety (n.) 1
guarantee, ratification, warrant
1H4 III.i.245 [Hotspur to Lady Percy] you ... givest such sarcenet surety for thy oaths
2H4 I.i.191 [Morton to Northumberland, of the Archbishop] He is a man / Who with a double surety binds his followers
H5 V.ii.364 [King Henry to French lords] we'll take your oath ... for surety of our leagues
KJ III.i.282 [Cardinal Pandulph to King Philip] thou ... makest an oath the surety for thy truth
LLL II.i.135 [King to Princess, of money owing] in surety of the which / One part of Aquitaine is bound to us
TC I.iii.220 [Agamemnon to Aeneas, offering him security] With surety stronger than Achilles' arm / 'Fore all the Greekish lords
TC V.ii.60 [Diomedes to Cressida, of her promise] Give me some token for the surety of it