When referring to a former leader of a country, one can use various synonyms for the term "ex-president". The most common terms are "former president" or "past president". Other synonyms include "outgoing president", "retired president", "previous president", and "former head of state". Depending on the context, one could also use "ex-leader" or simply refer to the individual by their name, followed by their former title, such as "Barack Obama, the former President of the United States". Regardless of the synonym used, the term refers to a person who previously held the highest office of a nation or state.