The term "more ill-behaved" suggests that someone's behavior is worse than it previously was. Antonyms for this phrase could include "better-behaved," "improved," "well-mannered," "polite," or "courteous." These words imply that the individual's behavior has improved and become more acceptable or appropriate. Alternatively, antonyms could include "well-behaved," "respectful," "mannerly," "well-mannered," or "civilized." These words suggest that the individual is polite and conducts themselves with decorum, just like we want children to behave. The choice of antonyms may depend on the context, but all of these words are useful in reference to individuals who are no longer acting out of control.