Define Dead Horse Jockey Meaning

Dead Horse Jockey
A person who continues, at length to continue on a topic that has exhausted its usefulness to the rest of the crowd, to expound and explore the dead topic.

Someone who, despite being told the topic is a "dead horse" continues to converse on that topic.

I can't believe Tim is still arguing about toothpaste with Bob, Bob agreed with him 20 minutes ago! What a dead horse Jockey.
By Liesa