1. The formation of a piece of or a fragment of lifeless bone removed from physically-fit bone because of an injury or disease: Dr. Jones and Dr. McMahon were puzzled as to why Marcus developed the sequestration in his left leg.
2. The isolation of a patient: Since Fay's daughter had a virus that was easily transmitted to others, she was placed in sequestration by the hospital staff.
3. A net increase in the quantity of blood within a limited vascular area: Medical sequestrations occur physiologically with or without the forward flow of blood persisting or are produced artificially by the application of tourniquets.
4. In common law, juries are often kept together and not allowed contact with other people during a trial and the jury deliberations until they are discharged and even the witnesses can be restricted: The prosecutor, Mr. Smith, believed defense witnesses might change their versions of the facts if they were permitted to hear the other witnesses testify; so, to avoid that problem, he requested that Judge Evans order the sequestration of all the witnesses. The judge agreed and so he ordered that all potential witnesses be placed in sequestration from the courtroom and each other until they were called to testify one at a time.
5. The effective removal of ions from a solution by coordination with another type of ion or molecule to form complexes that do not have the same chemical behavior as the original ions: It has been discovered that microbes may play a critical role in the sequestration of carbon in the oceans through a system termed the "microbial carbon pump", or MCP.
6. A description of a fiscal policy established by the U.S. Congress to limit the size of the federal government's excessive spending: The prospect of sequestrations seems to have become so catastrophic that Congress so far has been unwilling to let it actually happen.

Congress has repeatedly decided to raise the Budget Resolution spending limits upward toward the end of the legislative session in order to match the actual totals already appropriated; therefore, sequestration has largely diminished the incentives that the reformed budget procedures were supposed to provide for Congress to get better control of the budget deficit.

A congenital condition in which a mass of nonfunctioning lung tissue lacks a normal connection with the tracheobroncheal tree and receives an anomalous blood supply from a systemic branch of the thoracic aorta originating from the descending thoracic or abdominal aorta: The bronchopulmonary sequestration may be extralobar; that is, completely separated from the normally connected lung, or intralobar, which is partly surrounded by a normal lung.

A procedure in United States law that limits the size of the federal budget: Budget sequestration involves setting a limit on the amount of government spending.

The term sequestration was derived from a legal term referring to the seizing of property by an agent of a court, to prevent destruction or harm, until any dispute over such property is resolved in court.

The long-term accumulation of a substance; such as, carbon dioxide or radioactive waste, in a natural geologic formation, for example a sedimentary basin, seabed, or underground cavern: Jack and the geologists were exploring the possibilities of having a geological sequestration in the mountains.

A major demonstration of carbon dioxide injection into a saline formation for sequestration is underway at an offshore gas platform in the North Sea near Norway. Results from this project (and others) suggest that such formations will be reliable for long-term geologic sequestration (storage) sites or carbon dioxide reservoirs.

There are numerous natural carbon dioxide reservoirs throughout the Rocky Mountain states of the United States in geologic "domes" and "traps" suggesting these geological storage formations will be excellent for keeping carbon dioxide captured from industrial facilities.