Definition of entrenches:
(v) :
(figuratively) To establish a substantial position in business, politics, etc.
(v) :
(figuratively) To become completely absorbed in and fully accept one's beliefs, even in the face of evidence against it and refusing to be reasoned with.
(v) :
(military) To surround or provide with a trench, especially for defense; to dig in.
(v) :
(figuratively) 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.
(v) :
(construction, archaeology) To dig or excavate a trench; to trench.
(v) :
(literally) To cut in; to furrow; to make trenches in or upon.