To cut in; to furrow; to make trenches in or upon.
To surround or provide with a trench, especially for defense; to dig in.
To establish a substantial position in business, politics, etc.
To dig or excavate a trench; to trench.
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.
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.
To perforate with a trephine.
To use a trephine during surgery.
A surgical instrument with a cylindrical blade used to remove a circular section of tissue, f.e. bone or cornea; a trepan.