The quality or state of being commemorative; the characteristic of serving as or being intended as a commemoration.
From 'commemorative' (adjective) plus the noun-forming suffix '-ness', creating an abstract noun for the quality itself.
The commemorativeness of a simple photograph can be so powerful that it outlasts buildings and monuments, making physical objects less important than the memories they hold.
Complete word intelligence in one call. Free tier — 50 lookups/day.