Sequester 1: to set apart or segregate, as in sequester a jury. 2a: to seize, especially by a writ of sequestration. 2b: to place (property) in custody, especially in sequestration.
Today, "sequester" has a new meaning. The Office of Management and Budget declares on its website: "Sequester describes the practice of using mandatory spending cuts in the federal budget if the cost of running the government exceeds either an arbitrary amount or the gross revenue it brings during the fiscal year."
It would appear that the federal government has a whole lot of "sequestering" yet to do.