Eternity, seemingly without end, is a concept that has been around for centuries. The crossword solutions for this term are AGES (4 letters), EON (3 letters), and EONS (4 letters). AGES refers to a long period of time, while an EON is an even longer period of time, usually millions of years. EONS is the plural form of EON, indicating multiple periods of time. Together, these three words represent the idea of eternity, which is seemingly without end.