terrier

A dog from a group of small, lively breeds, originally bred for the hunting of burrowing prey such as rats, rabbits, foxes, and even otters; this original function is reflected in some of their names (e.g. rat terrier).

Someone displaying terrier-like qualities such as determined pursuit.

One of the LNER dispatch staff is a terrier when it comes to masks, challenging anyone without them.

A collection of acknowledgments of the vassals or tenants of a lordship, containing the rents and services they owed to the lord, etc.

An inventory (book or roll) in which the lands of private persons or corporations are described by their site, boundaries, number of acres, etc.; a terrar.

An auger or borer.