The term 'END OF AN ERA' can be solved with the three letter answer 'ERA'. This phrase is often used to describe a significant period of time that has come to an end, usually marked by a major event or change. It is often used to refer to the end of a political or cultural ERA, such as the end of a dynasty or the fall of a government. It can also be used to refer to the end of a personal ERA, such as the end of a relationship or the end of a career.