The most common and most likely answer to this crossword clue is the 7 plus 7 letter word ANCIENT HISTORY
I've seen this crossword clue in The Guardian
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More clues leading to the result ANCIENT HISTORY
- Old standard bearer fellow’s one on the right: we all know that?
- A tale about thin ice cracking is no longer relevant
- I enchant drunk with island tale that happened long ago
- I hit on ancestry unexpectedly — something obtained from old documents?
- As yet no Christian recollected what happened long ago
- Ruin intro with hesitancy — it’s no longer important!
- Rishi cannot yet dodge around this subject
Buddy explains!
The straight part
We know that "no longer relevant" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case no longer relevant = ancient history.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.