oath

noun

ˈōth 

plural oaths ˈōt͟hz 

ˈōths

1

a(1)

: a solemn usually formal calling upon God or a deity 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 of oath

• 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

Finally, in a twist on the classic Green Lantern oath from the comics, John personalizes the phrase with an emphasis on his newfound accepting of his fear. — Jordan Moreau, Variety, 5 Oct. 2026

After solving the mystery of his predecessor Hal Jordan’s (Kyle Chandler) death, Stewart claims Jordan’s power ring as his own, recites his oath and jets off toward his next adventure. — Tracy Brown, Los Angeles Times, 5 Oct. 2026

Now, there are plenty of reasons not to trust the devilish ex-Lantern who killed a Guardian, betrayed his oath, and urged Hal to kill John multiple times. — Ben Travers, IndieWire, 4 Oct. 2026

The Traitors take their oath, and Joe and Tomica are psyched to see each other. — Alice Burton, Vulture, 18 Sep. 2026

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