Undean

[…]said Mr. Slope, with a deanish sort of smirk on his face. […] Mr. Thorne gave him a look which undeaned him completely for the moment, but [Mr. Slope] soon remembered his high hopes […]

The nature of the role of former dean is developed through careful onboarding strategies for the new dean and interactions with a new set of constituents who perceive the dean as a former dean.