| Main Entry: | month of Sundays |
| Part of Speech: | noun |
| Definition: | forever |
| Synonyms: | ages, blue moon, dog's age, eternity, indefinitely long period, lifetime, time immemorial, when pigs fly |
| Main Entry: | donkey's years |
| Part of Speech: | noun |
| Definition: | very long time |
| Synonyms: | aeon, all one's born days, coon's age, eternity, forever and a day, long time, month of Sundays, right smart spell, time immemorial, time out of mind, years on end |
| Main Entry: | time immemorial |
| Part of Speech: | noun |
| Definition: | long time |
| Synonyms: | aeons ago, ages, eternity, month of Sundays, remote ages, time long past, time out of mind |
| Main Entry: | time out of mind |
| Part of Speech: | noun |
| Definition: | past beyond memory |
| Synonyms: | aeons ago, ages, auld lang syne, days beyond recall, long ago, long since, month of Sundays, remote ages, time immemorial |