"Penny missionary affairs", what's the meaning of this term ?
Edward, as a boy, had interested himself in Sunday-schools, debating societies, penny missionary affairs, anti-tobacco organizations, anti-profanity associations, and all such things;
Source: Edward Mills and George Benton - Mark Twain.
I think Mark Twain made the term up, as I've never heard it before. In the context it sounds to me like it's a fundraiser asking people to give small donations to missionaries. (Missionaries are people that go to other places (usually other countries) and preach their religious beliefs).