The phrase "good cause" can be replaced with a variety of synonyms to convey the idea of a noble or worthwhile reason. Some possible alternatives include "just cause," "noble cause," "worthy cause," "beneficial cause," "moral cause," "righteous cause," "valid cause," and "deserving cause." Each of these phrases emphasizes the idea that a particular action or cause is justified and deserves support or attention. By using different synonyms, writers and speakers can vary their language and create a more specific or nuanced meaning for their audience.