Merriam-Webster Online Dictionary
entrench (verb)transitive verb
1.
a) to place within or surround with a trench especially for defense
b) to place (oneself) in a strong defensive position
c) to establish solidly - entrenched themselves in the business
2.
intransitive verb
to cut into - furrow , specifically to erode downward so as to form a trench
1.
to dig or occupy a trench for defensive purposes
2.
to enter upon or take over something unfairly, improperly, or unlawfully - encroach used with on or upon
