Meaning: A very long time ago (used in nostalgic or mock-nostalgic recollection).
Synonyms: Past times, Yesteryear and time, History, Antiquity, Good old days, Days gone by, Time immemorial, Years ago.
In Hindi: गया काल
Use: In the days of yore, the Internet did not exist.
As a retiring teacher, I often recall the days of yore when a chalkboard was the main method of displaying lessons.
The writer’s novel transported us into the time of yore when dinosaurs ran freely on the planet.