entrench
verb [ T ]
uk/ɪnˈtrentʃ/ usto establish something firmly so that it cannot be changed:
This bold and comprehensive programme aims to restore growth, entrench low inflation, and reduce the public debt.
entrench yourself
to establish yourself firmly in a position, job, etc. so that it is difficult to remove you:
The company's management and directors have entrenched themselves by changing the voting requirements for expansion of the board.