διεγγυᾶν

From LSJ

οὕτως ἐξ ἐχθρῶν αὐτοκτόνα πέμπετο δῶρα, ἐν χάριτος προφάσει μοῖραν ἔχοντα μόρου → thus mutual gifts that bring death were bestowed by enemies, gifts that brought the lot of death in the name of a favor

Source

Greek > English (Woodhouse Verbs Reversed)

give security for a person, offer bail for (see also: διεγγυῶ, διεγγυάω)