intrench
verbless common spelling of entrench
1a
: 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
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