Scottish and English, now rare; a derivative of Arabella which has an uncertain origin.  Whyte suggests it is from Latin "yielding to prayer";  ONC acknowledges this and also notes the possible but less likely derivation as a spelling variant of Anabella.

In earlier centuries Orabel was an early variant of Arabel and it is possible this spelling was to refer to the Latin orabilis, "invokable", i.e. referring to a saint who could be invoked.