The most common and most likely answer to this crossword clue is the 6 letter word REFORM
R
E
F
O
R
M
More clues leading to the result REFORM
- Class with Scripture etc making one behave better
- Umpire, old, with room for improvement
- Improvement achieved in Bible class?
- Change making him hire?
- Change with regard to group of students
- Get back together, on condition
- “To be a better person is about being supportive” – May’s opener
- Whistler ‘Golden Maiden’ getting a make-over?
- Improve behaviour of soldiers with criminal record
- Improve group of students taking Religious Education
Buddy explains!

The straight part
We know that "behave better" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case behave better = reform.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 REFORM mean?
REFORM noun- The change of something that is defective, broken, inefficient or otherwise negative, in order to correct or improve it
- To put into a new and improved form or condition; to restore to a former good state, or bring from bad to good; to change from worse to better
- To return to a good state; to amend or correct one's own character or habits
- To form again or in a new configuration.