Possible Clues:

• Possessed, like a racehorse
• Completely dominated, in slang
• Had known editor, to an extent
• Held title
• Possessed the horse?
• ... had confessed
• What possessed you to sound so hurt, Edward?
• Half of endowments in need of adjustment to be fully paid off?
• Had day off - like a duck?
• Had broken down, found in possession of the note