Stakeholder

noun

1. A person holding the stakes of bettors, with the responsibility of delivering the pot to the winner of the bet.
2. An escrow agent or custodian.
3. A person filing an interpleader action, such as a garnishee or trustee, who acknowledges possession of property that is owed to one or more of several other claimants.
4. A person or organisation with a legitimate interest in a given situation, action or enterprise.