Noun
thing of the past (plural things of the past)
(idiomatic) Something that has gone extinct or become obsolete.
Well, the future for me is already a thing of the past. Bob Dylan
The harvest-home or supper is a thing of the past. To those who feel the fascination of the past this may appear sad, but it is not so really for, even while it existed, this surface goodwill was often an empty show. Flora Thompson
Spam will be a thing of the past in two years' time. Bill Gates
It is in the very nature of things human that every act that has once made its appearance and has been recorded in the history of mankind stays with mankind as a potentiality long after its actuality has become a thing of the past. Hannah Arendt
There's no such thing as an aura of mystery anymore. It doesn't exist. That's a thing of the past. Scarlett Johansson
Troy is a thing of the past. Latin Proverb