Entrench

Mid-16th century. - + trench

Full definition of entrench

(construction, archaeology) To dig or excavate a trench; to trench.
(military) To surround or provide with a trench, especially for defense; to dig in.The army entrenched its camp, or entrenched itself.
(figuratively) To establish a substantial position in business, politics, etc.

Senator Cornpone was able to entrench by spending millions on each campaign.
2013 September 28, Kenan Malik, "London Is Special, but Not That Special," New York Times (retrieved 28 September 2013)For London to have its own exclusive immigration policy would exacerbate the sense that immigration benefits only certain groups and disadvantages the rest. It would entrench the gap between London and the rest of the nation. And it would widen the breach between the public and the elite that has helped fuel anti-immigrant hostility.

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.

John LockeWe are not to intrench upon truth in any conversation, but least of all with children.