The meaning of SWEAR is to utter or take solemnly (an oath). How to use swear in a sentence.

SWEAR definition: to make a solemn declaration or affirmation by some sacred being or object, as a deity or the Bible. See examples of swear used in a sentence.

SWEAR definition: 1. to use words that are rude or offensive as a way of emphasizing what you mean or as a way of…. Learn more.

1. To have great reliance on or confidence in: He swears by his personal physician. 2. To have reliable knowledge of; be sure of: I think she left early, but I couldn't swear by it. 3. To take an oath by: He …

Definition of swear verb in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

Jan 20, 2026 · The witness swore that the person she had seen running out of the bank was a foot shorter than the accused. (transitive) To promise intensely that something is true; to strongly assert. I …

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 definition: declare something is true with emphasis. Check meanings, examples, usage tips, pronunciation, domains, and related words. Discover expressions like "swear at", "swear blind", …

swear: To make a solemn declaration, invoking a deity or a sacred person or thing, in confirmation of and witness to the honesty or truth of such a declaration.

If you say that you swear that something is true or that you can swear to it, you are saying very firmly that it is true.