do-gooder
 oxford
 views  updated May 23 2018do-good·er  / ˈdoō ˌgoŏdər/ •
n. a well-meaning but unrealistic or interfering philanthropist or reformer.DERIVATIVES: do-good adj. & n.do-good·er·y / -ərē/ n.do-good·ism / -goŏdˌizəm/ n.
 The Oxford Pocket Dictionary of Current English