Origin: OE. Othe, oth, ath, AS. A; akin to D. Eed, OS. E, G. Eid, Icel. Eir, Sw. Ed, Dan. Eed, Goth. Ais; cf. OIr. Oeth.
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. (bacon)
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. 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