Metanoia, an Ancient Greek word (μετάνοια) meaning “changing one’s mind”.
Metanoia is translated as repent most of the time in English language Bibles. However, reform might be closer to the original meaning. “Reform, for the Kingdom of Heaven is at hand.” (Matthew 4:17). I think only Young’s Literal Translation renders metanoia this way (read it here).
Metanoia is a fundamental change in thinking and living rather than a confession of sins as repentance is often explained.
How I intend to use the word metanoia.
Sometimes I try to avoid words which bring colour or meaning that they should not have. For example, the word repentance is so heavily charged, so thoroughly defined that it might not be fit for use in a particular discussion of doctrine. Where I wish to specifically refer to the radical change of heart and mind implicit in the original Greek, there I may use this word.