There are always times when you are having a conversation with someone, and that person is always correcting you or adding too many minor details to the points you are bringing up, so much so that the entire conversation feels less like a conversation and more like an uninteresting lesson. When this happens, and it does happen, the other person is being pedantic.
Pedantic describes someone or something that is overscrupulous, which means that they are excessively concerned with minor details or rules. Someone who is pedantic usually makes a big display of knowing obscure facts and details. They may also be too concerned with literal accuracy or formality. They are often know to point out corrections in unimportant and trivial details and often care more than necessary about formalities.
The term pedantic is often used today with a negative connotation. Here it describes someone who is very concerned and disturbed by small details and are very condescending to people who do not get those details right. They might even put down people or treat them as dumb if they do not know every single detail.
However, most people don’t realize that pedantry can be a symptom of a medical condition. People who are diagnosed with obsessive-compulsive personality disorder or with a specific developmental disorder, such as Asperger’s syndrome often depict behavior that is considered as pedantic.