A hole drilled or milled through something, or (by extension) its diameter.

“the bore of a cannon”

The tunnel inside of a gun's barrel through which the bullet travels when fired, or (by extension) its diameter.

A tool, such as an auger, for making a hole by boring.

To inspire boredom in somebody.

To make a hole through something.

To make a hole with, or as if with, a boring instrument; to cut a circular hole by the rotary motion of a tool.

“An insect bores into a tree.”