The most common and most likely answer to this crossword clue is the 3 plus 2 plus 5 letter word SET IN STONE
I've seen this crossword clue in Financial Times
S
E
T
I
N
S
T
O
N
E
More clues leading to the result SET IN STONE
- When troubled, is not tense or rigid.
- Schedule this month one absolutely fixed
- Some games of short tennis arranged and unlikely to be changed
- Group meeting this month, one absolutely fixed
- When wobbly, is net weight impossible to shift?
- Excalibur perhaps was, and is not going to change
- Schedule this month, one no longer changeable
- . Tension is not changeable
- Schedule this month’s one that can’t be changed
- Class this month one impossible to change
Buddy explains!
The straight part
We know that "that can’t be changed" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case that can’t be changed = set in stone.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.