Abjuration

[Zipporah Schumaker]

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.

[Jessica]

The art of magic involving the [banishing] or protection against creatures not from the world you are on. Usually [defensive] in nature. Also, you have to be a nerd to really get this. [Go figure].