Question: What is the nickname of the fictional surgeon who is married to show's protagonist Meredith Grey?
Sentence (from "Only Mama Knows (Grey's Anatomy)"): The episode focuses on the show's protagonist Meredith Grey's (Ellen Pompeo) past and troubled childhood and her relationship with her mother world-renowned surgeon Ellis Grey (Kate Burton) and Richard Webber (James Pickens Jr.) while she struggles in her marriage with Derek Shepherd (Patrick Dempsey).
Relevant evidence: Yes