The term 'A LONG, LONG TIME' can be expressed in several ways. The 3-letter solution 'AGO' refers to a period of time that has passed since a certain event or point in the past. The 3-letter solution 'EON' is a very long period of time, usually millions of years. The 4-letter solutions 'AGES' and 'AEON' are also very long periods of time, with 'AEON' being slightly longer than 'AGES'. The 4-letter solution 'EONS' is a plural form of 'EON', meaning multiple very long periods of time. Finally, the 5-letter solution 'AEONS' is a plural form of 'AEON', meaning multiple extremely long periods of time.