Entrenched

To dig or excavate a trench; to trench.

To surround or provide with a trench, especially for defense; to dig in.

"The army entrenched its camp, or entrenched itself."

To establish a substantial position in business, politics, etc.

"Senator Cornpone was able to entrench by spending millions on each campaign."

To invade; to encroach; to infringe or trespass; to enter on, and take possession of, that which belongs to another; usually followed by on or upon.