The correct answer is fortify.
B. cut grooves in wood
C. eat heartily
D. to fill trench
The correct answer is (A) To fortify by surrounding with a trench; to dig protective trenches. To surround or protect with a trench; to settle (oneself) securely, as in a job or some other position considered to be safe;
Entrench comes from Latin truncare (to cut).
Examples of use:
- The enemy soldiers are entrenched on this side of the closest hill.
- He was safely entrenched behind an undisputable alibi.