What is "oath of abjuration"

Abjuration \Ab`ju*ra"tion\, n. [L. abjuratio: cf. F. abjuration.]

1. The act of abjuring or forswearing; a renunciation upon oath; as, abjuration of the realm, a sworn banishment, an oath taken to leave the country and never to return.

2. A solemn recantation or renunciation; as, an abjuration of heresy.

   Oath of abjuration, an oath asserting the right of the present royal family to the crown of England, and expressly abjuring allegiance to the descendants of the Pretender.
   --Brande & C.

n. (context historical English) An oath asserting the right of the present royal family to the crown of England, and expressly abjuring allegiance to the descendants of http://en.wikipedia.org/wiki/Charles%20Edward%20Stuart, the http://en.wikipedia.org/wiki/Jacobitism.