'unceasingness' originates from Modern English, specifically formed from the adjective 'unceasing' + the noun-forming suffix '-ness', where the prefix 'un-' meant 'not' and the element 'cease' ultimately comes from earlier forms meaning 'to stop'.

'cease' passed into English from Old French 'cesser', which in turn comes from Latin 'cessare' (a frequentative of 'cedere' / 'to yield'); Middle English forms (such as 'cesen'/'ceasen') evolved into the modern English 'cease', and 'unceasing' developed by adding Old English/Modern English prefix 'un-' and present-participial formation 'ceasing' before '-ness' produced the full noun 'unceasingness'.

Initially, related roots such as Latin 'cessare' meant 'to stop' or 'to yield'; over time, English formed compounds and derivatives so that 'unceasingness' came to mean 'the quality of not stopping'—a continuous or uninterrupted state.