The most common and most likely answer to this crossword clue is the 10 letter word APOCRYPHAL
I've seen this crossword clue in The Guardian
A
P
O
C
R
Y
P
H
A
L
More clues leading to the result APOCRYPHAL
- Carol happy when drunk? That’s not true
- Approach case of leprosy with treatment of dubious validity
- Happy coral is damaged? That may not be true
- Happy with coral being destroyed without proper backing
- Carol happy to change? That’s questionable
- Happy carol that’s become legendary
- What could make Carol happy is questionable
- Happy with Carol, creatively made-up?
- Deliriously happy Carol is fabulous
- Letters from quiet royal chap may be spurious
Buddy explains!
The straight part
We know that "Questionable" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case questionable = apocryphal.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 APOCRYPHAL mean?
APOCRYPHAL adjective- Of, or pertaining to, the Apocrypha.
- (by extension) Of doubtful authenticity, or lacking authority; not regarded as canonical.
- (by extension) Of dubious veracity; of questionable accuracy or truthfulness; anecdotal or in the nature of an urban legend.