GAOL, or JAIL  , a prison (q.v.) . The two forms of the word are due to the parallel dual forms in Old Central and Norman French respectively, jaiole or jaole, and gaiole or geyolle . The common origin is the med . Lat. gabiole, a diminutive formed from caved, a hollow, a den, from which the English "cave " is derived . The form " gaol " still commonly survives in English, and is in official usage, e.g . " gaol-delivery," but the common pronunciation of both words, " jail," shows the real surviving word .