endorsement vs aegis

endorsement and aegis both are nouns.

Word	Noun	Adjective	Verb	Adverb
endorsement	Yes	No	No	No
aegis	Yes	No	No	No

As nouns, aegis is a hyponym of endorsement; that is, aegis is a word with a more specific, narrower meaning than endorsement:

Other hyponyms of endorsement include auspices, protection.

endorsement (noun)	aegis (noun)
the act of endorsing	kindly endorsement and guidance
formal and explicit approval	armor plate that protects the chest; the front part of a cuirass
a promotional statement (as found on the dust jackets of books)
a speech seconding a motion
a signature that validates something