A pedant is someone who pays too much attention to rules and to small, unimportant details — especially someone who points out other people’s tiny mistakes in a way that wears everyone down. They may be right about the little thing and still miss the big thing. Though actually, people use it loosely: sometimes they just mean “this person likes being correct”, which is not always unkind; the full, sharp meaning is “they use little facts to make you feel small”. It is a criticising word. You would not call a friend a pedant unless you were joking, or a bit angry. Today we usually keep pedant for the person and use pedantic for the adjective. It came from Italian pedante, “a teacher / schoolmaster”, and later picked up the unkind sense. People have long linked it in their heads with pedagogue; the two were associated, but they do not come from the same Italian word.

學究、愛挑小毛病的人