oath

noun

ˈōth 

plural oaths ˈōt͟hz 

ˈōths

1

a(1)

: a solemn usually formal calling upon God or a god to witness to the truth of what one says or to witness that one sincerely intends to do what one says

(2)

: a solemn attestation of the truth or inviolability of one's words

The witness took an oath to tell the truth in court.

b

: something (such as a promise) corroborated by an oath

They were required to swear an oath of loyalty.

took the oath of office

2

: an irreverent or careless use of a sacred name

broadly : swear word

He uttered an oath and stormed away.

Synonyms

• promise
• vow
• pledge

Examples of oath in a Sentence

an oath to defend the nation

He uttered an oath and walked away.

Recent Examples on the Web

Perhaps that should be a solemn oath for all AI makers. —Lance Eliot, Forbes.com, 2 Sep. 2025

Every lawmaker in Sacramento took an oath to uphold the California Constitution. —Suzette Valladares, Oc Register, 31 Aug. 2025

Each of them, including Raiola, the sophomore face of the program, signed an oath to uphold the Huskers’ standards. —Mitch Sherman, New York Times, 27 Aug. 2025

During my son’s white coat ceremony, parents who were physicians were invited to stand and recite the oath alongside their children. —Dana Suskind, Time, 27 Aug. 2025

Word History

Etymology

Middle English ooth, from Old English āth; akin to Old High German eid oath, Middle Irish oeth

First Known Use

before the 12th century, in the meaning defined at sense 1a(1)

Phrases Containing oath

• Hippocratic oath
• oath of office
• on oath
• under oath

Rhymes for oath

• both
• doeth
• growth
• loath
• quoth
• sloth
• troth
• ingrowth
• outgrowth
• undergrowth

Kids Definition

oath

noun

ˈōth 

plural oaths ˈōt͟hz 

ˈōths

1

: a solemn appeal to God or to some deeply respected person or thing to witness to the truth of one's word or the sincerity of a promise

under oath to tell the truth

2

: a careless or improper use of a sacred name

also : swearword

Medical Definition

oath

see hippocratic oath

Legal Definition

oath

noun

1

: a solemn attestation of the truth of one's words or the sincerity of one's intentions

specifically : one accompanied by calling upon a deity as a witness

2

: a promise (as to perform official duties faithfully) corroborated by an oath compare perjury