The term 'HISTORIC SEGMENTS' can be broken down into two crossword solutions: ERAS (4 letters). An era is a period of time in history that is defined by certain characteristics or events. It is usually used to refer to a long period of time, such as the Middle Ages or the Industrial Revolution. ERAS are often divided into smaller segments, such as decades or centuries, and these segments can be used to further define the characteristics of an era.