The antonyms for the word "un-changed" include several words that signify a state of alteration, transformation or modification. Some of the most common antonyms for "un-changed" are "altered", "transformed", "modified", "mutated", and "evolved". These words suggest a state of change or transition, where something is no longer the same as it used to be. Other antonyms that indicate a state of divergence from an original state include "diverse", "varied", "different", "new" and "reformed". Whatever the antonym used, the implication is that things have changed from the original state, either for better or worse.