The change of something that is defective, broken, inefficient or otherwise negative, in order to correct or improve it

“A major reform is needed to improve the efficiency in the factory.”

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

“1909, H. G. Wells, The History of Mr. Polly Chapter 9”

To return to a good state; to amend or correct one's own character or habits

“It is hoped that many criminals, upon being freed, will eventually reform.”

To form again or in a new configuration.

“The regiment reformed after surviving the first attack.”