adj
vested interest
a strong reason for wanting something to happen because you will gain from it
　Since he owns the strip of land, Cook has a vested interest in the project being approved.
vested interests
the groups of people who will gain from a plan, project, proposal etc
　The proposal faces tough opposition from powerful vested interests.
vested rights, powers, property etc belong to you and cannot be removed
　Shareholders have a vested right to 10% per annum.
technical having full rights to own or have something
become/get vested (in sth)
　He only took the job to get vested in the pension fund.