Emily Dickinson Lexicon

OATH, n. [Sax. ath; Goth. aiths; D. eed; G. eid; Sw. ed; Dan. æed.]

A solemn affirmation or declaration, made with an appeal to God for the truth of what is affirmed. The appeal to God in an oath, implies that the person imprecates his vengeance and renounces his favor if the declaration is false; or if the declaration is a promise, the person invokes the vengeance of God if he should fail to fulfill it. A false oath is called perjury.