The most common and most likely answer to this crossword clue is the 9 letter word UNTENABLE
I've seen this crossword clue in The Times
U
N
T
E
N
A
B
L
E
More clues leading to the result UNTENABLE
- Powerless to protect a cardinal? That’s insupportable!
- Not up to guarding ten? [That's] indefensible
- … empower crazy nut as leader? Indefensible
- Rocky powerless boxing figure
- UN support over prohibition sent up by Labour leader as indefensible
- Let a nun be put out? That’s indefensible
- Ridiculous nylon trousers, earrings, necklaces and tops in shocking blue
- Locally one’s beaten, left disfigured – that can’t be justified
- French articles about catch thrown back by sailor not based on facts
- Broadcast a blue film for No.10? It cannot be defended!
Buddy explains!
The straight part
We know that "indefensible" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case indefensible = untenable.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 UNTENABLE mean?
UNTENABLE adjective- Not able to be held, as of an opinion or position; unholdable, indefensible.
- Unfit for habitation