WordWeight : Weighing the Words

Pronunciation : Oath
Part of Speech : n.;
Etymology : [OE. othe, oth, ath, AS. a; akin to D. eed, OS. e, G. eid, Icel. ei, Sw. ed, Dan. eed, Goth. ai; cf. OIr. oeth.]
Definition : 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" Shak. 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. (Law)

Defn: 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" Shak.

pl. Oaths.
Source : Webster's Unabridged Dictionary, 1913