The term 'MAJOR SPANS' can be broken down into two crossword solutions: 'ERAS' (4 letters). The term 'ERAS' is used to refer to a period of time in history, usually a long period of time. It is often used to describe a period of significant change or development in a particular area. For example, the Industrial Revolution is often referred to as an era. In this context, 'MAJOR SPANS' could refer to a long period of time in which major changes or developments occurred.