The quality or capacity of being capable of being demonstrated, proven, or shown clearly.
From demonstrate (from Latin demonstrare: de- 'thoroughly' + monstrare 'to show') + -able (capable of) + -ity (the state or quality of). The root meaning is literally 'to show thoroughly.'
Science relies entirely on demonstrability—the idea that you can prove something by showing it to others—and this concept didn't become central to how humans think until the Scientific Revolution, completely changing what counts as 'knowledge.'
Complete word intelligence in one call. Free tier — 50 lookups/day.