1) Ephemeralness 2) Fleetingness 3) Something transitory 4) Transience 5) Transiency 6) Transitoriness 1) Ephemeralness 2) Fleetingness 3) Transience 
Ephemerality (from Greek εφήμερος – ephemeros, literally `lasting only one day`) is the concept of things being transitory, existing only briefly. Typically the term ephemeral is used to describe objects found in nature, although it can describe a wide range of things, including human artifacts intentionally made to last for only a tem.....
[n] - the property of lasting for a very short time
ephemeralness noun the property of lasting for a very short time
the quality or condition of being ephemeral. · something transitory.