ε3981Ἐχέγγυος
secure, security-providing, trustworthy
[Meaning] a secure guarantor; one [who is considered] valuable because of [his] credit. In Thucydides [it means] someone/something strong, able to provide security.
Ἐχέγγυος· ὁ ἀσφαλὴς ἐγγυητής· ὁ διὰ πίστεως ἄξιος. παρὰ δὲ Θουκυδίδῃ ἰσχυρόν, ἐγγυῆσαι δυνάμενον.