The most common and most likely answer to this crossword clue is the 8 letter word OBSOLETE
I've seen this crossword clue in The Guardian
O
B
S
O
L
E
T
E
More clues leading to the result OBSOLETE
- Out-of-date old boys look back, wanting summer in Paris
- Old boy has a couple of teeth to eat fish that’s out of date
- Ancient honour accepted just one time
- Son tucked into mushroom after duck that’s out of date
- Lose old bet newly regarded as invalid
- Old one, team’s leader, held in honour
- Single to be excited about having dated
- Fish in batter to be past its sell-by date
- Repaired bootees left inside, no longer used
- Dead fish taken in to be cooked
Buddy explains!
The straight part
We know that "out of date" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case out of date = obsolete.The cryptic/wordplay part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.
What does OBSOLETE mean?
OBSOLETE adjective- (of words, equipment, etc.) No longer in use; gone into disuse; disused or neglected (often by preference for something newer, which replaces the subject).
- Imperfectly developed; not very distinct.
- To cause to become obsolete.