The most common and most likely answer to this crossword clue is the 6 plus 2 plus 5 letter word CHANGE OF HEART
I've seen this crossword clue in The Sunday Telegraph
C
H
A
N
G
E
O
F
H
E
A
R
T
More clues leading to the result CHANGE OF HEART
- Going back on decision to have transplant operation?
- U-turn? If you do that, you might get to the A4 without you texting
- What Scrooge had to replace with compassion
- Hater? Maybe he needs it
- Earth-shattering volte-face?
- Altered attitude that could make son sin?
- Transplant earth?
- Revision of attitude that’s produced by major operation
- What could be Earth’s second 5
- Earth’s revised opinion?
Buddy explains!
The straight part
We know that "Revision of attitude" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case revision of attitude = change of heart.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.