aegis Look up aegis at Dictionary.com
"protection," 1793, from L. ęgis, from Gk. Aigis, the shield of Zeus, said by Herodotus to be related to aix (gen. aigos) "goat," from PIE *aig- "goat" (cf. Skt. ajah, Lith. ozys "he-goat"), as the shield was of goatskin. Athene's aigis was a short goat-skin cloak, covered with scales, set with a gorgon's head, and fringed with snakes.