do-gooder

• dogooder

do good +‎ -er

do-gooder (plural do-gooders)

1. (derogatory) One who advocates a certain course of action, often of political or social concern, and often with the naive conviction of their own moral superiority.

   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.

   • 1979, Monty Python's Life of Brian, spoken by Ex-Leper (Michael Palin):

     I was hopping along, minding my own business. All of a sudden, up he comes, cures me. One minute I'm a leper with a trade, next minute my livelihood's gone. Not so much as a by-your-leave! “You're cured mate.” Bloody do-gooder.