"Expel" refers to the act of forcing someone or something to leave a place or organization. This term is often used in educational settings, where a student may be expelled from school due to serious misconduct or violation of rules. The process typically involves a formal review and decision by school authorities. In a broader context, expulsion can occur in various environments, such as workplaces or countries. For example, a government may expel a foreign diplomat for actions deemed inappropriate. The term can also apply to the removal of substances, like expelling air from a balloon when it is squeezed.