What is the meaning of Vested_interest?

An indefeasible right or title, distinguished from a contingent interest, which could be defeated (i.e. cease) if a certain event occurred.

A fixed right granted to an employee, especially under a pension plan.

A stake, often financial, in a particular outcome.

A group of people or organizations with such a stake, especially those that seek to control an existing system or activity from which they derive benefit.

An exceptionally strong interest in protecting or promoting something to one's own advantage.

Source: wiktionary.org