The term 'Forever and a Day' is often used to describe something that will last for an extremely long time. The crossword solutions for this term include EON (3 letters), EONS (4 letters), AEON (4 letters), ETERNITY (8 letters), AGES (4 letters), BLUEMOON (8 letters), and DONKEYSYEARS (12 letters). EON and EONS refer to an indefinitely long period of time, while AEON is a variant spelling of the same word. ETERNITY is another word for an infinite amount of time, and AGES is a synonym for a very long period of time. BLUEMOON is a phrase that means 'once in a lifetime, ' and DONKEYSYEARS is an idiom that means 'a very long time.' All of these words and phrases are used to describe something that will last for an indefinite amount of time, which is the meaning of the phrase 'Forever and a Day.'