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.

Is there such a word as Boringness?

adj. Uninteresting and tiresome; dull. bor′ing·ly adv. bor′ing·ness n.

Is boredom a noun or adjective?

BOREDOM (noun) definition and synonyms | Macmillan Dictionary.