A. The title means preacher. It’s rarely used nowadays, but was more common in Eastern Europe in the 200 years leading up to the Holocaust. It can go either way.
Rebbe Dov Ber, the successor to the Baal Shem Tov was called the Maggid of Mezeritch, and the Koznitzer Maggid (of the story I like to tell about Shabse & Mrs. Bookbinder) was a later Chassidic Rebbe, too. In fact, the Alter Rebbe of Chabad, was at one time called the Liozner Maggid.
In non-Chassidic (Misnagdic) circles you also find famous people with the Maggid title, such as the Dubner Maggid (famous for his parables) and the Maggid of Kelm, among others.
There was a time, especially prior to the Chassidic movement, that fire and brimestone Maggid(im) would speak firmly and harshly to the simple folks with vivid imagery of harsh punishment, and the switch to a positive focus was a hallmark of the Chassidic movement.