(transitive, formal) To take an oath on someone or something.

Swearing (as a witness) persistently to what is false; perjury.

(informal) To vigorously affirm the truth of a statement, knowing that the failure to do so may result in a punishment from God.

(informal) Used to indicate that the speaker is swearing to God.

plural of swearing contest

(law, informal) A trial whose outcome comes down to which of two parties swearing to the truth of opposing accounts is to be believed.

Ellipsis of swear on a stack of Bibles.

(simile) To swear a lot; to utter many swear words.

To make a promise or give an assurance with great conviction.

(simile) Synonym of swear like a trooper