The most common and most likely answer to this crossword clue is the 7 letter word DEFUNCT
I've seen this crossword clue in The Guardian
D
E
F
U
N
C
T
More clues leading to the result DEFUNCT
- American officer, rejected by UN court, no longer working
- Not working is enjoyable in period around Christmas time
- No longer used in part of nationwide functions
- Trade function essentially obsolete
- Expired time after amusement in December
- No longer working in December, time filled with merriment
- Diversion during last month takes junction out of use
- Dead river caused an unpleasant smell, so it’s said
- No more in-the-nude functions
- Handy to keep foreign article on computer programming language becoming obsolete
Buddy explains!

The straight part
We know that "Dead/Dead" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dead/dead = defunct.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 DEFUNCT mean?
DEFUNCT noun- The dead person (referred to).
- To make defunct.
- Deceased, dead.
- No longer in use, inactive.
- Specifically, of a program: that has terminated but is still shown in the list of processes because the parent process that created it is still running and has not yet reaped it. See also zombie, zombie process.
- No longer in business or service.
- (of a language) No longer spoken.