What is the meaning of Containment?

The state of being contained.

The state of containing.

Something contained.

A policy of checking the expansion of a hostile foreign power by creating alliances with other states; especially the foreign policy strategy of the United States in the early years of the Cold War.

A physical system designed to prevent the accidental release of radioactive or other dangerous materials from a nuclear reactor or industrial plant.

An inclusion.

Source: wiktionary.org