to make a solemn declaration or affirmation by some sacred being or object, as a deity or the Bible.

to bind oneself by oath.

to give evidence or make a statement on oath.

to use profane oaths or language

Don't swear in front of the children.

to declare, affirm, attest, etc., by swearing by a deity, some sacred object, etc.

to affirm, assert, or say with solemn earnestness.

to promise or undertake on oath or in a solemn manner; vow.

to testify or state on oath

He swore it on the witness stand.

to take (an oath), as in order to give solemnity or force to a declaration, promise, etc.

to bind by an oath

to swear someone to secrecy.

swear by,

to name (a sacred being or thing) as one's witness or guarantee in swearing.

Informal . to have great confidence in; rely on

He swears by his dentist.

to have certain knowledge of

I thought I saw him leaving, but I couldn't swear by it.

swear in, to admit to office or service by administering an oath

A new president will be sworn in today.

swear off, to promise or resolve to give up something, esp. intoxicating beverages.

swear out, to secure (a warrant for arrest) by making an accusation under oath.

verb

affirm , assert , attest , avow , covenant , cross one’s heart , depend on , depose , give one’s word , give witness , have confidence in , maintain , make an affidavit , pledge oneself , plight , promise , rely on , say so , state , state under oath , swear by , swear to god , swear up and down , take an oath , testify , trust , vouch , vow , warrant , bedamn , be foul-mouthed , blaspheme , curse , cuss , execrate , flame * , imprecate , take name in vain , talk dirty , use bad language , utter profanity , damn , witness , adjure , anathematize , asseverate , declare , depone , expletive , oath , perjure , pledge , threat , use profane language

phrasal verb

break off , desist , discontinue , give up , leave off , quit , relinquish , remit , stop