A renunciation of allegiance to a country by oath.
The act of Congress of the 14th of April, 1802, requires that when an alien shall apply to be admitted a citizen of the United States, he shall declare on oath or affirmation before the court where the application shall be made, inter alia, that he doth absolutely and entirely renounce and abjure all allegiance and fidelity which he owes to any foreign prince., and particularly, by name, the prince whereof he was before a citizen or subject.
In England the oath of abjuration is an oath by which an Englishman binds himself not to acknowledge any right in the Pretender to the throne of England.
It signifies also an oath abjuring to certain doctrines of the church of Rome.
In the ancient English law it was a renunciation of one's country and taking an oath of perpetual banishment. A man who had committed a felony, and for safety flea to a sanctuary might within forty days' confess the fact, and take the oath of abjuration and perpetual banishment; he was then transported. This was abolished.