aegis

noun

ae·​gis ˈē-jəs 

also

ˈā- 

variants or less commonly egis

1

: a shield or breastplate emblematic of majesty that was associated with Zeus and Athena

2

a

: protection

under the aegis of the Constitution

b

: controlling or conditioning (see condition entry 2 sense 5a) influence

passed new laws under the aegis of national security

3

a

: auspices, sponsorship

under the aegis of the museum

b

: control or guidance especially by an individual, group, or system

under the aegis of the government

Did you know?

Aegis Has Greek and Latin Roots

English borrowed aegis from Latin, but the word ultimately comes from the Greek noun aigís, meaning “goatskin.” In ancient Greek mythology, an aegis was something that offered physical protection. It has been depicted in various ways, including as a magical protective cloak made from the skin of the goat that suckled Zeus as an infant, and as a shield fashioned by Hephaestus that bore the severed head of the Gorgon Medusa. The word first entered English in the 15th century as a noun referring to the shield or breastplate associated with Zeus or Athena. It later took on a more general sense of “protection” and, by the late-19th century, it had acquired the extended senses of “auspices” and “sponsorship.”

Synonyms of aegis

• defense
• protection
• shield
• ammunition
• safeguard
• wall
• weapon

Examples of aegis in a Sentence

having no claim to the land under the aegis of the law, the cattle baron decided to claim it by force

a medical study that was questioned by many because it was done under the aegis of a major pharmaceutical company

Recent Examples on the Web

His tenure of just a few months overlapped with that of then-UCSD student Marc Geiger, who booked six rock shows shows that first season under the aegis of Marc Berman Concerts. —George Varga, San Diego Union-Tribune, 8 Mar. 2026

Crime abhors a vacuum, and in Tommy’s absence, the Peaky Blinders gang has reformed under the aegis of his sociopathic illegitimate son Duke (Barry Keoghan). —Damon Wise, Deadline, 5 Mar. 2026

Unlike sportsbooks, prediction markets are available in all 50 states, operating under the aegis of the federal Commodity Futures Trading Commission (CFTC) rather than state regulation. —Dan Bernstein, Sportico.com, 5 Mar. 2026

Two years later, Israel and the Palestinians, under the aegis of the Clinton administration, launched the Oslo peace talks. —Ron Kampeas, Sun Sentinel, 2 Mar. 2026

Word History

Etymology

borrowed from Latin, borrowed from Greek aigís "goatskin, mantle of Zeus," derivative of aig-, aíx "goat"; akin to Armenian aic "goat" (perhaps going back to Indo-European *h₂eiǵ-ih₂-), and perhaps to Avestan izaēna "of leather"

First Known Use

15th century, in the meaning defined at sense 1

Rhymes for aegis

• egregious

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Kids Definition

aegis

noun

ae·​gis ˈē-jəs 

1

: protection sense 1a, defense

under the aegis of the law

2

: patronage sense 1, sponsorship

under the aegis of the museum