According to some etymologies, it is "ajar more than it should". This termination is perhaps an influence of French outrager; because in fact it comes from the latin ultraticum ("transfer limit"). It is used figuratively, to moral, ethical, limits of education and propriety: without prejudice to, in addition, a physical insult.
* Only one "like" per meaning and day, the more "likes" the meaning will appear higher in the list