Definition from Wiktionary, the free dictionary
do-gooder (plural do-gooders)
- (derogatory) One who advocates or performs what they believe to be the morally superior course of action, even in the face of overwhelming experience or factual evidence that its effect is only irrelevant or harmful.
- Prohibition in the United States was an unsuccessful attempt by do-gooders to save people from the dangers of alcohol, whether they wanted to be saved or not.
One who performs what they believe to be the morally superior course of action