- strips the title and leaves the person standing. gives o, gives o, gives o, gives o. The root keeps its ending, and the prefix works as a verb root in its own right: is to dismiss somebody, is to resign.
It needs a role that can be held and then lost. o is nonsense, because nobody stops being a father, and native-feeling Esperanto simply refuses the combination.
For former in the weaker sense of earlier, reach for antaŭa or iama instead. And note that is the act of divorcing, not a vague memory of having once been married.