ægis

from The Century Dictionary.

• noun In Greek myth, originally the storm-cloud enveloping the thunderbolt, the especial weapon of Zeus; afterward considered as the skin of the goat Amalthea, the foster-mother of Zeus, which the latter took for defensive armor in his war with the Titans.
• noun In art, a representation of the ægis as a sort of mantle fringed with serpents, much more ample in archaic examples than later, generally worn covering the breast, but sometimes held extended over the left arm, or thrown over the arm to serve as a shield.
• noun Hence, figuratively Any influence or power which protects: as, under the imperial ægis. Also spelled egis.

from the GNU version of the Collaborative International Dictionary of English.

• noun A shield or protective armor; -- applied in mythology to the shield of Jupiter which he gave to Minerva. Also fig.: A shield; a protection.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Alternative spelling of aegis.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun kindly endorsement and guidance
• noun armor plate that protects the chest; the front part of a cuirass