Eterne' Eterne is an adjective derived from the Latin word 'aeternus, ' meaning eternal or everlasting. It is often used to describe something that is timeless and unchanging. In the context of a crossword puzzle, the term 'Eterne' could refer to something that has been around for a long time, or something that will remain unchanged for a long period of time. The three-letter solution for this term is 'EER, ' which stands for 'enduring, eternal, or everlasting.'