1) Dig in 2) Dig in solidly 3) Establish 4) Fasten 5) Firmly implant 6) Fix firmly or securely 7) Impinge or infringe upon 8) Implant 9) Install 10) Intrench 11) Secure 12) Take a defensive position 13) To cut in 14) To dig in 15) To dig or excavate a trench 16) To encroach 17) To furrow 18) To infringe or trespass 1) Digin 2) Impinge 3) Implant 4) Intrench 
• (v. t.) See Intrench.
En·trench' transitive verb See Intrench . 
[v] - occupy a trench or secured area 2. [v] - fix firmly or securely
verb occupy a trench or secured area; `The troops dug in for the night`intrench verb fix firmly or securely
to place in a position of strength; establish firmly or solidly: safely entrenched behind undeniable facts. · to dig trenches for defensive purposes around (oneself, a military position, etc.).