διασφαλίζομαι
From LSJ
ψυχῆς πείρατα ἰὼν οὐκ ἂν ἐξεύροιο πᾶσαν ἐπιπορευόμενος ὁδόν· οὕτω βαθὺν λόγον ἔχει → one would never discover the limits of soul, should one traverse every road—so deep a measure does it possess
English (LSJ)
A secure firmly, Plb.5.69.2, Ph.Byz.Mir.4.2, Herod. Med. ap. Orib.8.7.3:—Pass., σιδήρῳ διησφαλισμένα J.AJ15.11.3.