The term 'many, many years' can be expressed in a variety of ways. The crossword solutions for this term include 'EONS' (4 letters), 'EPOCH' (5 letters), 'AEON' (4 letters), 'AGES' (4 letters), and 'EON' (3 letters). EONS are the longest unit of geological time, and are typically divided into eras, periods, and epochs. An AEON is an indefinite long period of time, usually associated with eternity. AGES are a longer period of time than years, but shorter than EONS. Finally, an EON is the longest unit of geological time, and is typically divided into eras, periods, and epochs.