The term 'Momentous Stretches' can be summarized as a period of time that is significant and long-lasting. The crossword solution for this term is 'ERAS', which refers to a long and distinct period of time in history or the development of a particular thing. An era is typically marked by a certain set of characteristics, such as a particular style of art or a political movement. It is often used to refer to a period of time in which a particular culture or civilization flourished.