1.A solemn affirmation or declaration, made with a reverent appeal to God for the truth of what is affirmed. "I have an oath in heaven" "An oath of secrecy for the concealing of those (inventions) which we think fit to keep secret."
2.A solemn affirmation, connected with a sacred object, or one regarded as sacred, as the temple, the altar, the blood of Abel, the Bible, the Koran, etc.
3.(Law) An appeal (in verification of a statement made) to a superior sanction, in such a form as exposes the party making the appeal to an indictment for perjury if the statement be false.
4.A careless and blasphemous use of the name of the divine Being, or anything divine or sacred, by way of appeal or as a profane exclamation or ejaculation; an expression of profane swearing. "A terrible oath"
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