(n.) The quality of being incessant; unintermitted continuance; unceasingness.

ceaselessness chattering coeternity consecutiveness constancy constant flow continualness continuance continuity continuousness durability endlessness equilibrium eternalness eternity ever-duringness everlastingness everness featurelessness foreverness fullness gaplessness immutability indestructibility infinite duration infinity interminability jointlessness monotony never-endingness noninterruption oscillation perdurability perenniality perennialness permanence perpetualness perpetuity plenitude pulsation quick fire rapid fire rapid recurrence rapid succession rapidity regularity repetition seamlessness sempiternity smoothness stability staccato steadiness steady state stuttering successiveness sustainment tattoo timelessness unbrokenness unceasingness undifferentiation uniformity unintermission unintermittedness uninterruptedness uninterruption unrelievedness vibration