(derogatory) Advocating or performing a supposed morally superior course of action, even in the face of overwhelming experience or factual evidence that its effect is only irrelevant or harmful.

(derogatory) The actions or attitudes of a do-gooder.

To act virtuously. / To contribute positively; to aid.

(idiomatic) To achieve social acceptance or financial success as a result of behaving in a benevolent or charitable manner.