A / aegis
noun

aegis

gen. aegĭdis · gender feminine · decl. 3rd
= αἰγίς, ίδος.
The œgis
The œgis.
The shield of Jupiter
The shield of Jupiter, Verg. A. 8, 354; Sil. 12, 720.—
The shield of Minerva; with Medusa's head
The shield of Minerva, with Medusa's head, Verg. A. 8, 435: contra sonantem Palladis aegida, Hor. C. 3, 4, 57; so Ov. M. 2, 753; 6, 78 al.—Hence,
by extension
A shield; defence
A shield, defence.—So only Ovid of the jewelry by which maidens try to conceal their ugliness: decipit hac oculos aegide dives Amor, R. Am. 346.—
the wood nearest the pith
In the larch-tree, the wood nearest the pith, Plin. 16, 39, 73, § 187.