The quality or state of being tedious, dull, and uninteresting.
From 'boring' (adjective) plus the abstract noun suffix '-ness', allowing speakers to treat tedium as a quantifiable quality or characteristic.
Unlike 'boredom' which is what you *feel*, 'boringness' is what the thing *is*—it's an important distinction in how we talk about blame: a lecture isn't boring because you're bored, it's boring because of its inherent quality.
Complete word intelligence in one call. Free tier — 50 lookups/day.