The Collaborative International Dictionary of English v.0.48:

aegis \ae"gis\ ([=e]"j[i^]s), n. [L. aegis, fr. Gr. a'igi`s a
   goat skin, a shield, a'i`x goat, or fr. 'ai`:ssw to rush.]
   A shield or protective armor; -- applied in mythology to the
   shield of Jupiter which he gave to Minerva. Also fig.: A
   shield; a protection.
   [1913 Webster]

V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006):

AEGIS
       Advanced Electronic Guidance and Instrumentation System


Moby Thesaurus II by Grady Ward, 1.0:

107 Moby Thesaurus words for "aegis":
   abetment, advocacy, arm guard, armament, armor, auspices, backing,
   backstop, bard, beaver, brassard, breastplate, buckler, buffer,
   bulletproof vest, bulwark, bumper, care, championship, charity,
   coif, contraceptive, copyright, corselet, countenance,
   crash helmet, cuirass, cushion, dashboard, dodger, encouragement,
   face mask, favor, fender, finger guard, foot guard, fosterage,
   fuse, gas mask, gauntlet, goggles, goodwill, governor, guard,
   guardrail, guidance, habergeon, hand guard, handrail, hard hat,
   hauberk, headpiece, helm, helmet, insulation, interest, interlock,
   jamb, knee guard, knuckle guard, laminated glass, life preserver,
   lifeline, lightning conductor, lightning rod, lorica, mail, mask,
   mudguard, nasal, nose guard, pad, padding, palladium, patent,
   patronage, pilot, plate, preventive, prophylactic, protection,
   protective clothing, protective umbrella, rondel, safeguard,
   safety, safety glass, safety plug, safety rail, safety shoes,
   safety switch, safety valve, screen, seat belt, seconding,
   security, shield, shin guard, sponsorship, sun helmet, sympathy,
   tutelage, umbrella, visor, ward, windscreen, windshield