Ἁλοσύδνη
From LSJ
θεωρεῖται δὲ ἀνοησίᾳ κρείττονι νοήσεως → it is grasped only by means of an ignorance superior to intellection, it may be immediately cognised only by means of a non-intellection superior to intellection
English (LSJ)
ἡ, epith. of Thetis, Il.20.207; νέποδες καλῆς ἁλοσύδνης, of seals, Od.4.404 (expl. by Gramm. as 'child of the sea'); of Nereids, A.R.4.1599; cf. ὑδατοσύδνη. (Perh. containing the root of ὕδωρ.)