vested interest

vested interest　既得权益，既得利益　

1.right of ownership，possession，and use of a tangible or intangible property that is immediate（or is certain to come about）and which（unlike a contingent interest）is not dependent on something that may or may not happen.Not to be confused with vested in interest.2.personal stake or expectation of personal gain that underlies a strong commitment to maintain or influence an action.