Other forms: borings
As an adjective boring describes something (or someone) that is tedious, dull, and lacking in interest. As a noun, boring refers to the act of drilling a hole, or the hole itself.
When a geologist's powerful drill makes a boring into the earth, you can remove a sample and learn about the history of our planet just by seeing what's contained in the boring's layers. Of course, if you aren't interested in that kind of thing, you might find a two-hour lecture on the subject a bit boring.