The term 'A Very Long Period of Time' can be summarized by the word 'AEON', which is a four-letter word. An AEON is an indefinite and very long period of time, often used to describe a period of time that is so long that it cannot be measured. It is often used to refer to a period of time that is longer than a human lifespan. In some cases, it is used to refer to a period of time that is so long that it is difficult to imagine or comprehend.