What is the meaning of Preemption?

An act or process that preempts; a preventive or forestalling action; as:

  1. The purchase of something before it is offered for sale to others.
  2. The purchase of public land by the occupant.
  3. The temporary interruption of a task without its cooperation and with the intention of resuming it at a later time.
  4. The displacement of a lower jurisdiction's laws when they conflict with those of a higher jurisdiction.

The purchase of something before it is offered for sale to others.

The purchase of public land by the occupant.

The temporary interruption of a task without its cooperation and with the intention of resuming it at a later time.

The displacement of a lower jurisdiction's laws when they conflict with those of a higher jurisdiction.

Source: wiktionary.org