Bleeding Deacon 

In the context of a 12-step program like Alcoholics Anonymous, a bleeding deacon is someone in the group who is overly preachy and considers themselves to be the lone voice of reason and source of wisdom. In the eyes of the bleeding deacon, the group would fall apart without them.

Alcoholic 1: "Randy really droned on for a while about the eighth step -- I get it, we're supposed to make direct amends. Sheesh."

Alcoholic 2: "Yeah, he's a real bleeding deacon."

Bleeding Deacon by Joe Incognito November 30, 2010