What is Rehabere Facias Seisinam?

Legal Definition
When a sheriff in the "habere facias sei-sinam" had delivered seisin of more than he ought, this judiclal writ lay to make him restore seisin of the excess. Reg. Jud. 13, 51, 54
-- Black's Law Dictionary
Legal Definition
A writ to compel a sheriff to repossess a plaintiff after having seised the defendant of more than he should under a habere facias seisinam.
-- Ballentine's Law Dictionary