The most common and most likely answer to this crossword clue is the 3 plus 5 letter word ALL THERE
I've seen this crossword clue in The Guardian
A
L
L
T
H
E
R
E
More clues leading to the result ALL THERE
- Implying no one here mentally alert
- Everybody present and of sound mind
- A full set of marbles for everyone present
- Presumably nobody here is alert
- Nothing unaccounted for on one’s trolley, presumably?
- Now out of silver, not nuts
- Everyone’s turned up with a full picnic
- Sane? Completely so!
- Missing a froth in beer is perfectly rational
- Forestall the rest, keeping alert
Buddy explains!
The straight part
We know that "A full set of marbles/everyone present" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a full set of marbles/everyone present = all there.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.