The word "sequester" is a verb. It has three meanings. The first meaning of sequester is to put somebody in an isolated or lonely place away from other people, away from the pressures of everyday life and away from possible disturbances. A judge can order a jury to be sequestered if it's important that they aren't influenced by those outside the courtroom setting.
The second meaning is a definition in regard to law. It means to take legal possession of someone's property temporarily until a debt that person owes is paid, or until a dispute is settled or a court order is obeyed. The guys at the pawn shop, for instance, might sequester my guns and jewelry until I pay them back.
The third meaning is a definition in regard to international law. It means to demand or seize the property of an enemy. During World War II, the Nazis sequestered lots of valuable stuff from the French.
Reading these definitions, I wondered which one was most related to the budget sequestration we're experiencing today. The second meaning seems most likely. Since the federal budget is over its previously-agreed-upon cap, the Treasury will take legal possession of 85-billion dollars temporarily until Congress and the president settle their current dispute.
The third meaning relates, though, too, but only if you regard the government as the enemy of the people. And if that's the case, the government is seizing the proposed property of its enemy.
Personally, I like the first definition. When I think of putting somebody in an isolated or lonely place away from other people, "government sequestration" seems like the best idea we've ever had.