Oath is a solemn appeal to a deity, or to some revered person or thing, to witness one's determination to speak the truth, to keep a promise. A statement or promise strengthened by such an appeal. A formally affirmed statement or promise accepted as an equivalent of an appeal to a deity or to a revered person or thing affirmation. The form of words in which such a statement or promise is made. An irreverent or blasphemous use of the name of God or anything sacred and any profane expression curse swear word.